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Maintenance Tips On Cars. - Car Talk (51) - Nairaland

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Re: Maintenance Tips On Cars. by Nobody: 7:36pm On Nov 12, 2017
GAZZUZZ:


migration be a scam
OK!
So, i'll just assume this is all just a big mistake and you didnt just label me a scam for no apparent reason. Diagnosis is as easy as ABC, so i needn't explain that, the role of diagnosis in predictive maintenance is equally as straightforward. Pabambari e, the products i sell are available for hand delivery in lagos and Ibadan, and everywhere else through konga. I think we should refrain from throwing caution to the wind, and be more careful. I would personally be absolutely sure and have facts before i libel another.
Re: Maintenance Tips On Cars. by GAZZUZZ(m): 7:39pm On Nov 12, 2017
Gilbertase:

OK!
So, i'll just assume there is all just a big mistake and you didnt just label me a scam for no apparent reason. Diagnosis is as easy as ABC, so i needn't explain that, the role of diagnosis in predictive maintenance is equally as straightforward. Pabambari e, the products i sell are available for hand delivery in lagos and Ibadan, and everywhere else through konga. I think we should refrain from throwing caution to the wind, and be more careful. I would personally be absolutely sure and have facts before i libel another.

read the rules.

If you did read the rules and decided not to follow them I will label you as it fits.
Re: Maintenance Tips On Cars. by jossytech(m): 10:43pm On Nov 12, 2017
@ Gazzuzz attend to us
Re: Maintenance Tips On Cars. by AutoElectNG: 4:41pm On Nov 13, 2017
olaboy1:


Gaz.zuzz is it not better to first know if the ECM is giving a rich command that makes additional raw fuel get into the CAT, just changing the CAT might not be the best fix.

I’m having same issue for P0420 and P0430 and I’ve changed CAT and DTC’s persist. I can tell from my LTFT that it is taking fuel from the negative readings or am I wrong. I have seen a video on YouTube and the fix was the previous mechanic that installed the downstream oxygen sensors misplaced their positions. In my case I personally had all my sensors identified by tape with positions they were suppose to be boldly written on them, but my mechanic with his “you can’t teach me my job” mentality just mixed everything together and said all the plugs are not the same and no way you can make a mistake on this installation.

After seeing the YouTube video, I realised my mechanic was half right because the upstream oxygen sensors connectors are not the same but the downstream sensors are, so I am working on checking if the sensors are sitting in their right positions.

STFT Bank 2 at idle hovering between 2.34 to 7.81
STFT Bank 1 at idle hovering between 2.34 to 7.81 (I thought they should be close to zero as much as possible)

What are you trying to solve?

You bought a used CAT if I remember correctly, which is not the best thing to do, everything considered. Are you chasing after P0420 and P0430? Or something else?
Re: Maintenance Tips On Cars. by olaboy1: 5:06pm On Nov 13, 2017
AutoElectNG:


What are you trying to solve?

You bought a used CAT if I remember correctly, which is not the best thing to do, everything considered. Are you chasing after P0420 and P0430? Or something else?

My LTFT are always in the negatives around minus 8% which leads me to believe I have an underlying issue destroying my CAT.
Will a bad CAT cause my LTFT’s to be like that. I just don’t want to change to a new CAT that would be destroyed again. Two things I’m yet to troubleshoot are vacuum leaks and injectors.
Any idea how to go about this?
See upstream and downstream sensors behavior, maybe you can use those and the LTFT’s to point me in the right direction. I thought the upstream sensors should be switching rapidly, but they both seem to stay longer on the high voltage.
Also I’m confused because my freeze frame data on fuel trims when I get CAT DTC’s are always within spec at the time the DTC set, but when I park and check my fuel trims, the LTFT’s are always wack.

Re: Maintenance Tips On Cars. by AutoElectNG: 1:25am On Nov 14, 2017
olaboy1:


My LTFT are always in the negatives around minus 8% which leads me to believe I have an underlying issue destroying my CAT.
Will a bad CAT cause my LTFT’s to be like that. I just don’t want to change to a new CAT that would be destroyed again. Two things I’m yet to troubleshoot are vacuum leaks and injectors.
Any idea how to go about this?
See upstream and downstream sensors behavior, maybe you can use those and the LTFT’s to point me in the right direction. I thought the upstream sensors should be switching rapidly, but they both seem to stay longer on the high voltage.
Also I’m confused because my freeze frame data on fuel trims when I get CAT DTC’s are always within spec at the time the DTC set, but when I park and check my fuel trims, the LTFT’s are always wack.

It can be argued that apart from the inputs obtained from the ECT sensor, the oxygen sensor(s) is the next most important input the OBD II system needs to function properly.

By function properly, I mean that problems with the oxygen sensors have been known to shut down the OBD II monitoring system. Conversely, the OBD II monitoring system should be able to tell us if oxygen sensors are out of order.

Thus far, you have relied on an OBD II scanner.

I am going to suggest a change of method and tools.

There are three things you need to test separately:

1. Oxygen sensor rich voltage accuracy (plot voltage over time using 200mV/Div and 500mS/Div)

2. Oxygen sensor lean voltage accuracy (plot voltage over time using 200mV/Div and 500mS/Div)

3. Oxygen sensor response speed i.e., how fast it can make the transition from full rich to full lean, most important consideration of them all(plot voltage over time using 200mV/Div and 500mS/Div)

You will need propane gas and a DSO.

You keep getting the P0420 and the P0430 because the OBD II monitors feel something is amiss.

So we have to test each component in the chain.

The purpose of this test is to rule out that your oxygen sensors are not fooling the OBD II monitoring system and by extension the PCM through the provision of inaccurate data.

The theory behind my proposal is this:

1. simulate a test/laboratory rich scenario and measure the voltage which would be compared with what it ought to be from the specification sheet of the oxygen sensor manufacturer

2. simulate a test/laboratory lean scenario and measure the voltage which would be compared with what it ought to be from the specification sheet of the oxygen sensor manufacturer

3. simulate a test/laboratory scenario in which it adjusts from full lean to full rich and measure how fast it recognizes/reads the change which would be compared with what it ought to be from the specification sheet of the oxygen sensor manufacturer.

If we can guarantee that the oxygen sensors are good, then we can look at the other components in the chain. But if they are bad, then we may have found the source of the recurrent P0420 AND P0430

--------------------
MODIFIED BELOW
---------------------
OLABOY1

Two OBD II monitors are at play here. The Oxygen Sensor Monitor and the CAT Monitor. What if I may ask is the readiness status of the Oxygen Sensor Monitor? I want to assume that the CAT Monitor is not ready.

The function of the CAT is to take care of incomplete combustion and convert hazardous waste (NOx, HC and CO into CO2 and water).
To do this, the CAT depends heavily on a correct A/F ratio which is attained when the mixture switches between rich and lean. When rich, the CAT is most efficient at the conversion of NOx to CO2 and water, when lean, the CAT is most efficient at the conversion of HC and CO to CO2 and water.

This poses the question: Has your ride attained and is it capable of maintaining stoichiometric ratio and is it capable of oscillating moderately between rich and lean?

From your understanding of vehicle operation, you know the centrality of the role of the oxygen sensor and by extension the oxygen sensor monitor in managing/observing that this is going well.

Yet another question arises in the circumstances: Are your front oxygen sensors functioning properly? The question is relevant because the Air/Fuel ration has to be just right for the CAT to function optimally.

From the foregoing explanation, the front oxygen sensors provide the input that the CAT Monitor uses to do its job (in addition to fuel trim adjustments) WHILE the CAT monitor compares the signals from the front oxygen sensor and the signals from the rear oxygen sensor to determine CAT efficiency.

This may help you better appreciate why I have asked that you answer the question first and foremost – are my oxygen sensors behaving the way the way they were programmed to do or is something amiss before we go any further.

While an OBD Scanner can provide some of this information, a DSO is a better tool to get at that information, hence the suggestion that you switch method and tools.
Re: Maintenance Tips On Cars. by ukata16(m): 8:00am On Nov 14, 2017
Oga @GAZZUZZ good morning.
Please when will you go to Port Harcourt again for auto works? Told an uncle about your works and I am trying to see if you will meet with him. The last port harcourt flood damaged his Prado jeep, some quacks did works but the car still has many issues, mechanical and electrical. It's a 2015 or 16 Prado jeep.
Thanks
Re: Maintenance Tips On Cars. by olaboy1: 4:52pm On Nov 22, 2017
I have been in contact on WhatsApp with AutoElectNG, such a fantastic guy with a huge wealth of experience in automotive diagnosis.
I followed all the vital information he outlined in his last post to the last letter.
My personal advice in case a car DIY enthusiast is reading this is to get these two things before proceeding with any troubleshooting.
1. Technical bulletins on your car factory service manual. This will give you a comprehensive lists of all the parameters and values your car should meet.
2. A reliable scan tool that can read all the information derived from point 1 above.

AutoEletNG streamlined the troubleshooting to oxygen sensors behaviors (upstream and downstream), and his reason was because of OBD monitor test for CAT not completed. The oxygen sensors were behaving erratically, and he advice I do an engine/ECU software update.

The ECU software update fixed all my fuel trims within spec and car drives smoother, and whilst comparing all technical data from FSM with live data on the scantool, I realized Evap VSV was OFF instead of ON, and that may probably be the cause of what has been damaging my CAT by causing my A/F and oxygen sensors to behave erratic, unfortunately no DTC was set for this Evap VSV (http://alflash.com.ua/evap.htm).

I shall give more update here on the final fix whilst I work closely with AutoElectNG.

Re: Maintenance Tips On Cars. by olaboy1: 4:58pm On Nov 22, 2017
More pixs

Re: Maintenance Tips On Cars. by GAZZUZZ(m): 5:32pm On Nov 22, 2017
Quite impresive....
Re: Maintenance Tips On Cars. by olaboy1: 6:49pm On Nov 22, 2017
I took the car to the biggest Toyota dealership here before and they couldn’t identify the problem after all computer and scan tests.
I went to two other well equipped workshops and same thing.....(sir there is nothing wrong with your car).

But from my driving experience and the performance of my other car, It’s so easy to spot that the car is performing like a bone stuck in the throat of a gluttonous child.

My only confusion right now is that Evap monitor shows complete while CAT monitor shows incomplete. Although I’m yet to fulfil the drive cycle for CAT monitor test and the pending CAT DTC’s were already there before all I’ve just done on the car.

So the only way to tell if this is a fix is to complete CAT cycle monitor test, and drive for another 2-3 weeks to see if the pending CAT DTC’s would come up, as they usually do around 2-3weeks. Below is a screenshot of all the MONITORS done by the scantool.

I am open to further expert advice on why my Evap VSV is showing “OFF”.

Re: Maintenance Tips On Cars. by obekediamondfuto(m): 8:34pm On Nov 22, 2017
interesting, and I tot I read someone saying diagnosis IS as easy as ABC..... maybe not this thread
Re: Maintenance Tips On Cars. by AutoElectNG: 11:06pm On Nov 22, 2017
olaboy1:
I took the car to the biggest Toyota dealership here before and they couldn’t identify the problem after all computer and scan tests.
I went to two other well equipped workshops and same thing.....(sir there is nothing wrong with your car).

But from my driving experience and the performance of my other car, It’s so easy to spot that the car is performing like a bone stuck in the throat of a gluttonous child.

My only confusion right now is that Evap monitor shows complete while CAT monitor shows incomplete. Although I’m yet to fulfil the drive cycle for CAT monitor test and the pending CAT DTC’s were already there before all I’ve just done on the car.

So the only way to tell if this is a fix is to complete CAT cycle monitor test, and drive for another 2-3 weeks to see if the pending CAT DTC’s would come up, as they usually do around 2-3weeks. Below is a screenshot of all the MONITORS done by the scantool.

I am open to further expert advice on why my Evap VSV is showing “OFF”.

The CAT Monitor depends on data from the oxygen sensors.

The Oxygen Sensor Monitor needs to run before the CAT monitor runs.

I know you already know this: that you need to meet the enabling criteria for your particular vehicle for the CAT monitor to run successfully.

The CAT monitor tests the efficacy of the CAT.

I have started work on the EVAP VSV OFF but EVAP Monitor complete.

I'll provide feedback when I am done.
Re: Maintenance Tips On Cars. by olaboy1: 4:26pm On Nov 26, 2017
obekediamondfuto:
interesting, and I tot I read someone saying diagnosis IS as easy as ABC..... maybe not this thread

It’s tricky actually, especially if you don’t have DTC or the DTC you have is tied to the proper function of other sub-system. So you need to start isolating the malfunction of those sub-systems one by one which is very tedious.

But I think it’s much easier for mechanics who have been in the game for long and who have all required equipment to test e.g dyno test, compression test, emission test etc.

Also you need to consider the thresholds set for some of these sub-systems to throw DTC’s are high, and you may have a malfunctioning part but yet to throw a DTC.
Re: Maintenance Tips On Cars. by depair: 5:25pm On Nov 26, 2017
hello pls i have the following code on my car Toyota camry 2001 I4 engine P0128 P0420 P0440 P0441 P0446
please what is the way out
Re: Maintenance Tips On Cars. by GAZZUZZ(m): 5:40pm On Nov 26, 2017
depair:
hello
pls i have the following code on my car
Toyota camry 2001
I4 engine
P0128
P0420
P0440
P0441
P0446

please what is the way out

p0128. No thermostat installed in theremostat housing, and fans connected to work with ignition.

P0420, bad or absent catalyst bank1.

P0440-446 evaporative emmision issues.

Return theremostat return connections back to normal and replace radiator.

Replace catalyst (if you can find a good one) evacuate catalyst and ignore catalyst code if you cannot find a replacement.

For evaporative emmission codes, start by ensurin fuel pump assembly seals are seating properl, ensure no vacuum leaks from fuel tank. If you can ensure this and problem still exists, contact your car doctor for further treatment.
Re: Maintenance Tips On Cars. by depair: 7:57pm On Nov 26, 2017
GAZZUZZ:


p0128. No thermostat installed in theremostat housing, and fans connected to work with ignition.

P0420, bad or absent catalyst bank1.

P0440-446 evaporative emmision issues.

Return theremostat return connections back to normal and replace radiator.

Replace catalyst (if you can find a good one) evacuate catalyst and ignore catalyst code if you cannot find a replacement.

For evaporative emmission codes, start by ensurin fuel pump assembly seals are seating properl, ensure no vacuum leaks from fuel tank. If you can ensure this and problem still exists, contact your car doctor for further treatment.

the thermostat is there, the fans are not direct they come on when the enhine is warm

will check the fuel lines but i hope i can trace it very well

any effect on the vehicle in the absence of the catalyst
Re: Maintenance Tips On Cars. by GAZZUZZ(m): 8:52pm On Nov 26, 2017
depair:


the thermostat is there, the fans are not direct they come on when the enhine is warm

will check the fuel lines but i hope i can trace it very well

any effect on the vehicle in the absence of the catalyst

are you sure? Do not confuse thermostat and thermistor. operation of fans is determined by thermistor in this case.

If thermostat is present, it could be a case of it being stuck open.
Re: Maintenance Tips On Cars. by depair: 10:56am On Nov 27, 2017
GAZZUZZ:


are you sure? Do not confuse thermostat and thermistor. operation of fans is determined by thermistor in this case.

If thermostat is present, it could be a case of it being stuck open.

how can i know a good thermostat in the market.
Re: Maintenance Tips On Cars. by GAZZUZZ(m): 12:38pm On Nov 27, 2017
depair:


how can i know a good thermostat in the market.

in the market not possible. Take it home, throw it into a pot of water, watch it open when water starts to boil, and close when temp drops below 82deg Celsius.

Re: Maintenance Tips On Cars. by HenryWilliams(m): 9:35pm On Nov 27, 2017
Evening..
Please how can I return my radiator fans back to factory specs.
Recently bought a car with fans wired directly.. And I'm not too comfortable with such. .thanks
Re: Maintenance Tips On Cars. by AutoElectNG: 5:49am On Nov 28, 2017
HenryWilliams:
Evening..
Please how can I return my radiator fans back to factory specs.
Recently bought a car with fans wired directly.. And I'm not too comfortable with such. .thanks

I can help with that

2 Likes

Re: Maintenance Tips On Cars. by adanny01(m): 6:06am On Nov 28, 2017
ayogabriel:
Good day people i use honda accord 06 model. The stereo use to work fine, until it suddenly makes a pop sound and goes of.

Presently it only comes on but no sound. The kazeem i invited to check it, said i have to change the stereo.

Having check online, i found out its a general problem with honda accord. Please can angbody help me out if there is another way,before i spend money that i could save for something else? Thanks all

There is a solution to it online. Continue looking.

1 Like 1 Share

Re: Maintenance Tips On Cars. by HenryWilliams(m): 10:59am On Nov 28, 2017
AutoElectNG:


I can help with that

In which way pls.
I'm not really a "fan" of such practices.
Re: Maintenance Tips On Cars. by AutoElectNG: 11:41am On Nov 28, 2017
HenryWilliams:


In which way pls.
I'm not really a "fan" of such practices.

By reverting the connections to factory in a less than a day.
Re: Maintenance Tips On Cars. by HenryWilliams(m): 12:20pm On Nov 28, 2017
AutoElectNG:


By reverting the connections to factory in a less than a day.

I'll love to see you do that.. How can I get hold of you?
Re: Maintenance Tips On Cars. by AutoElectNG: 12:27pm On Nov 28, 2017
HenryWilliams:


I'll love to see you do that.. How can I get hold of you?

Chat me..number in my signature
Re: Maintenance Tips On Cars. by viazi: 2:02pm On Nov 28, 2017
Put an 02 sensor spacer on the post catalyst O2 sensor to solve the p0420

GAZZUZZ:


p0128. No thermostat installed in theremostat housing, and fans connected to work with ignition.

P0420, bad or absent catalyst bank1.

P0440-446 evaporative emmision issues.

Return theremostat return connections back to normal and replace radiator.

Replace catalyst (if you can find a good one) evacuate catalyst and ignore catalyst code if you cannot find a replacement.

For evaporative emmission codes, start by ensurin fuel pump assembly seals are seating properl, ensure no vacuum leaks from fuel tank. If you can ensure this and problem still exists, contact your car doctor for further treatment.
Re: Maintenance Tips On Cars. by viazi: 2:04pm On Nov 28, 2017
Thanks for this engine saving info.
GAZZUZZ:


in the market not possible. Take it home, throw it into a pot of water, watch it open when water starts to boil, and close when temp drops below 82deg Celsius.

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