Good day my honourable members of this erudite car forum.
Please i use a toyota camry i4(EFI,DOHC) LE,1999 model.
I had check light for almost a year and, but recently got a car scanner(small but mighty ELM 327 usb scanner). Really had a poor gas mileage like 12.5 mpg city driving.
After initial scan, the following codes popped up:
P0505
P0171
P1135
P0401
Actions Taken:
I cleared the codes, but later the codes came back, i had to visit a panel beater to wield the leakages on the exhaust system, this cleared the P0401, but first 3 codes still stayed on, changed the air intake hose(actually had a serious crack on it, my car hard been jerking while on slow movement).
These actions helped my car but still had a poor gas mileage.
Observations:
Recently the car has started jerking, and the following codes are still on: P0505(idle control malfunction
P0171(system too lean)
P1135(air/fuel sensor bank 1 malfunction).
Noticed also my spark plugs has a black soot on them.

Please guys please help me out. I'm out of ideas on what to do, complained this to 3 different mechanic(but these guys are so clueless, i wonder how they learnt their trade)
I really want to solve these problems and more importantly increase my MPG.
Attached is screen dump of the live data from the scan(excel file) .
Thanks guys in anticipation.

nonso84: Good day my honourable members of this erudite car forum.
Please i use a toyota camry i4(EFI,DOHC) LE,1999 model.
I had check light for almost a year and, but recently got a car scanner(small but mighty ELM 327 usb scanner). Really had a poor gas mileage like 12.5 mpg city driving.
After initial scan, the following codes popped up:
P0505
P0171
P1135
P0401
Actions Taken:
I cleared the codes, but later the codes came back, i had to visit a panel beater to wield the leakages on the exhaust system, this cleared the P0401, but first 3 codes still stayed on, changed the air intake hose(actually had a serious crack on it, my car hard been jerking while on slow movement).
These actions helped my car but still had a poor gas mileage.
Observations:
Recently the car has started jerking, and the following codes are still on: P0505(idle control malfunction
P0171(system too lean)
P1135(air/fuel sensor bank 1 malfunction).
Noticed also my spark plugs has a black soot on them.

Please guys please help me out. I'm out of ideas on what to do, complained this to 3 different mechanic(but these guys are so clueless, i wonder how they learnt their trade)
I really want to solve these problems and more importantly increase my MPG.
Attached is screen dump of the live data from the scan(excel file) .
Thanks guys in anticipation.

@ OP,
P0505(idle control malfunction)
P0171(system too lean)
P1135(air/fuel sensor bank 1 malfunction)

Check these places, allied parts and where necessary, replace these parts.

For your P0505 code, it refers to your Idle Air Control switch. It might be bad, it might have a loose connection, its motor might be stuck.


For P0171 code, it refers to a downstream Oxygen sensor which could be triggered when The MAF (Mass Air Flow) Sensor is dirty or faulty
Failed or faulty oxygen sensor (bank 1, sensor 1)
Sticking/plugged or failed fuel injector Low fuel pressure (possible plugged/dirty Sticking/plugged or failed fuel injector Low fuel pressure (possible plugged/dirty fuel
filter) Exhaust leak between engine and first oxygen sensor. If you're going to fix it, try these steps

A lot of times, cleaning the MAF sensor and finding/fixing vacuum leaks fix the problem. If you're on a tight budget, start there, but that may not be the fix for certain. So, possible solutions
include:
*Clean the MAF sensor. Consult your service
manual for it's location if you need help. I find it's best to take it off and spray it with electronics cleaner or brake cleaner. Make sure you are careful not to damage the MAF sensor, and make sure it's dry before reinstalling
*Inspect all vacuum and PCV hoses, replace/repair as required
*Inspect all hoses and connections in the air intake system
*Inspect and/or test the intake manifold gaskets
for leakage
*Check for a dirty fuel filter and proper fuel
pressure

For P1175 code, check the AF sensor in the picture I uploaded and replace if faulty.

Your air filter needs replacement if you've not replaced it for a long while.
Your MAF, vacuum tubes, exhaust or out-take pipes from the body of the engine to the main exhaust pot and the catalytic converters needs to be inspected, if its got error and can't be corrected, change it.
If your Oxygen and/or Air Fuel mix ratio sensor aren't working change them.
When you've done corrections clear the co

Thanks Boss.

(upstream a/f sensor) that will solve the black sooth on the plugs, fix the bad fuel mileage.
(Idle control malfunction) will fix stalling and erratic rpms.

Note: your 1999 camry does not use an MAF, intead it uses MAP, and it does not have any servicable parts. Just ensure the vacuum hose is fitted properly, or if your in doubt just replace it, a tokumbor one costs 1k-1.5k.

Hello Guys i have replaced my air/fuel bank 1 sensor 1 (o2 sensor) and fuel filter but the problem persist.
Now the car jerks like a bull on traffic and shuts off and gas mileage has gone crazy(p0171 still comes up).
My STFT & LTFT is still high, check for vaccuum leaks, though i noticed oil enters through the mass/air flow filter from the pcv from the engine head.
Guys i need serious suggestions please.
N/b: I am still a newbie on cars, pls use simple terms.

nonso84: Hello Guys i have replaced my air/fuel bank 1 sensor 1 (o2 sensor) and fuel filter but the problem persist.
Now the car jerks like a bull on traffic and shuts off and gas mileage has gone crazy(p0171 still comes up).
My STFT & LTFT is still high, check for vaccuum leaks, though i noticed oil enters through the mass/air flow filter from the pcv from the engine head.
Guys i need serious suggestions please.
N/b: I am still a newbie on cars, pls use simple terms.

You may just consider changing the car, I mean Sell it.

Bossmd:
You may just consider changing the car, I mean Sell it.

Bros why say so? I need technical input.

nonso84:
Bros why say so? I need technical input.

Yes....I understand. Just that after trying everything suggested by the auto experts here and it still doesn't work out fine it could be frustrating.

Anyway you can still keep trying, another better suggestion is that you should consider replacing the engine totally. Your car's engine is not all that expensive. That could take care of all these problems once and for all.

Bossmd:

You may just consider changing the car, I mean Sell it.

I am really disappointed at you. Your car had problems, u came here and everybody tried to help u solve it. And this is what u have to tell someone else whose problem is peanut to what your car has. Y have u not sold urs? Op, are u sure the AF sensor u bought is good? No be tokunboh u buy? Buy brand new sensor, buy recommended plugs (new), clean ur injector nozzles and check ur vacuum hose system properly

@op your car needs a complete tune up. Check your fuel pump and your fuel filter, change spark plugs, service inlet manifold, service your injector noozles and lastly check your throttle actuator. Thank me later

chukel: I am really disappointed at you. Your car had problems, u came here and everybody tried to help u solve it. And this is what u have to tell someone else whose problem is peanut to what your car has. Y have u not sold urs? Op, are u sure the AF sensor u bought is good? No be tokunboh u buy? Buy brand new sensor, buy recommended plugs (new), clean ur injector nozzles and check ur vacuum hose system properly

@Chukel don't get me wrong. The Op has done almost everything advised and he said the problem still persists. I did the same to my previous car, the CEL just didn't go away and the car always does overheating on the highway with the AC on.....what did I do? I sold the car to get a new one.....some cars can really give you headaches seriously......Imagine the op's present Fuel consumption is worse than that of a V8 Range Rover. That is tantamount to holes in the pocket.

Anyway I hope he finds a lasting solution soon. I wish him all best.

But what is the problem with our mechanics in Nigeria. Don't we have certified automotive technicians in Nigeria? I mean people who have some basic theoretical knowledge of Automobile Engineering.

Most of these roadside mechanics are technically clueless!

Thanks Guys for all your assistance. I ended up changing my injector, spark plugs, new a/f sensor,smoke sensor(map sensor), bought new catalyst and covered all leaking spots on my exhaust.

Bossmd post=282n64:


@Chukel don't get me wrong. The Op has done almost everything advised and he said the problem still persists. I did the same to my previous car, the CEL just didn't go away and the car always does overheating on the highway with the AC on.....what did I do? I sold the car to get a new one.....some cars can really give you headaches seriously......Imagine the op's present Fuel consumption is worse than that of a V8 Range Rover. That is tantamount to holes in the pocket.

Anyway I hope he finds a lasting solution soon. I wish him all best.

But what is the psroblem with our mechanics in Nigeria. Don't we have certified automotive technicians in Nigeria? I mean people who have some basic theoretical knowledge of Automobile
Engineering.

Most of these roadside mechanics are technically clueless!

Bro simply admit that you didn't meet the right person to help you out when you had issues with your car. Saying some1 should change an engine without knowing the cause of a problem is just a No for me. If you were to be client and I told you we needed to change your engine just for a jerking issue. It wouldn't speak good of how competent one is. Another reigning trend is after a client must have wasted enough money to quack mechanics and they eventually meet the right person to fix the car. They begin to say all kind of things and even offer you something to low that cant even buy parts needed to fix the ride. When there is a problem the culprit should be brought to book. Have seen cases where the same way you asking the op to change his engine . Nothing positive came out of it and even in cases of changing a whole transmission

UPDATED:
Hi guys, all the above problem's been resolved.
Had a wrong wiring done by a roadside rewire(he bypassed some wires and connected the idle control wrongly) corrected by a more experienced rewire, p0505 is gone, o2 sensors codes gone and p0171 gone.
Infact the car now runs like when i just got it from the US.
Thanks all for the suggestions, i remain an ardent fan of cartalk section.
God bless you all.

bros pls wher did u buy the sensors i need some sensor for my car too. i wont mind d person contact

I got from ladipo market.
You can check from the guys that sell exhaust.