Please feel free to relate all your 2001-2006 santa fe problems and how you solved them.

I own a 2002 santa fe 4wd 2.4L I4. It came 2nd hand with a lot of issues but he worst was the poor engine power output and hiigh fuel consumption (about 8mpg city; 10mpg hgwy). Even more bizzare was how the power output kept fluctuating while driving. The first time I took it out of lagos trailers were overtaking me on steep grades. I tried changing the nozzles and after changing out several sets including a very expensive set I bought on ebay for 27k I finally got the message- it wasn't my injector nozzles.

Next I focused on the exhaust system and the first thing I found was that it didn't come with any O2 sensors. Instead it had an air-to-fuel ratio potentiometer which the computer used to calculate the mix. At the same time I had noticed that the engine sound was realy poor. Closer inspection revealed that most of the exhaust system had bbeen swapped out and replaced with old mecedes benz ehhaust mufflers most likely by the mechanics who had kept the car befor it was sold to me. So instead of just buying a tokunbo exhaust, I decided to do a tune up. I replaced the rear muffler with an original tokunbo santafe muffler but decide to replace the middle pot with a brand new high performance cherrybomb muffler. Since I wasn't sure that the potentiometer was still functional, I decided to buy a brand new O2 sensor which I wired in to my car computer using the potentiometer circuit. The difference in performance was almost instantaneous and fuel consumption improved but was still hovering around 12-13mpg, nowhere near the manufacturers touted 21mpg for my 2.4L engine. Besides power output was still fluctuating and acceleration was very poor.

After several months of managing it like this I decided to do further research which prompted me to clean up the hydraulic valve lifters and recalibrate the timing belt. Still no improvement. I read somwhere that faulty throttle and MAP sensors could cause the symptoms I was encountering so I had all of them changed including the crank sensor, all to no avail. I had changed all myy spark plugs, intake and exhaust valves so I decided that I was definitely looking at an electrical problem.

One of the first things I'd noticed when I got the car was the degree of rewiring that it had undergone with many loose wires and extraneous relays lying around. I decide to download the schematics from www.hmaservice.com and do a careful re building of the engine electrical system. While doing this, I found a loose wire in the engine compartment fuse box that had been cut and rerouted. This single wire was the signal from the ecm to the ecu relay that controlled the timing of fuel from the nozzles. It had been rerouted to get power ddirectly from the ignition lock. I restored this connection and found that my engine would crank but no longer start. In other words, the part of the computer responsible for fuel management was not functional. The onlyy way to find out why was to have the car scanned.

To my surprise, the tech who scanned it said there was no response from the computer (ecm) and that he couldn't access it. We were both puzzled and had to get down to the innards. We finally found the answer at the ignition lock. There is a small antenna in the ring arround the ignition lock that activates the chip in the key and then transmits the code released from the key into the immobilizer chip in the ecm. If the code corresponds to the ecm programming, the immobilizer releases the fuel management and/or ignition systems and permits the car to start. This antenna was completely missing from my car.

Without it there was no way the ecm could give the signsl to the nozzles to release fuel and start the car so some smart rewire simply cut the wire and got the signal directly from the ignition. Unfortunately in doing this the car no longer had access to signals from the throttle, crank, MAP and MAF sensors all of which are important in helping the ecm calculate efficient utility of fuel and ensure smooth output of power.

I am now waiting for him to buy the antenna and fix it. Hopefully, this will solve the problem. Will keep u updated.

Excellent trouble shooting.
I sure hope the car looks good enough for you to have bought it with these issues, or you bought it extremely cheap.

Hmmm....to fix this fuel problem...did you already spend more than what you paid for the car? I hope the antenna is the last uou have to spend on and hope the car rides brand new after.

nissparts: Excellent trouble shooting.
I sure hope the car looks good enough for you to have bought it with these issues, or you bought it extremely cheap.

The truth is I knew next to nothing about cars when I bought it. This car took me to school.

Well then, trust me, this is a worthwhile experience even if you lose some money in the process.
The knowledge you will gain sorting this out will come in handy even when dealing with other cars in the future.

Thickson:
The truth is I knew next to nothing about cars when I bought it. This car took me to school.

Very akin to my experience since 2010. You forthrightness is commendable.

Thickson:
The truth is I knew next to nothing about cars when I bought it. This car took me to school.

Ah ah?....I had no doubt you were a mechanic!Props to you bro!

Thickson:
Please feel free to relate all your 2001-2006 santa fe problems and how you solved them.

I own a 2002 santa fe 4wd 2.4L I4. It came 2nd hand with a lot of issues but he worst was the poor engine power output and hiigh fuel consumption (about 8mpg city; 10mpg hgwy). Even more bizzare was how the power output kept fluctuating while driving. The first time I took it out of lagos trailers were overtaking me on steep grades. I tried changing the nozzles and after changing out several sets including a very expensive set I bought on ebay for 27k I finally got the message- it wasn't my injector nozzles.

Next I focused on the exhaust system and the first thing I found was that it didn't come with any O2 sensors. Instead it had an air-to-fuel ratio potentiometer which the computer used to calculate the mix. At the same time I had noticed that the engine sound was realy poor. Closer inspection revealed that most of the exhaust system had bbeen swapped out and replaced with old mecedes benz ehhaust mufflers most likely by the mechanics who had kept the car befor it was sold to me. So instead of just buying a tokunbo exhaust, I decided to do a tune up. I replaced the rear muffler with an original tokunbo santafe muffler but decide to replace the middle pot with a brand new high performance cherrybomb muffler. Since I wasn't sure that the potentiometer was still functional, I decided to buy a brand new O2 sensor which I wired in to my car computer using the potentiometer circuit. The difference in performance was almost instantaneous and fuel consumption improved but was still hovering around 12-13mpg, nowhere near the manufacturers touted 21mpg for my 2.4L engine. Besides power output was still fluctuating and acceleration was very poor.

After several months of managing it like this I decided to do further research which prompted me to clean up the hydraulic valve lifters and recalibrate the timing belt. Still no improvement. I read somwhere that faulty throttle and MAP sensors could cause the symptoms I was encountering so I had all of them changed including the crank sensor, all to no avail. I had changed all myy spark plugs, intake and exhaust valves so I decided that I was definitely looking at an electrical problem.

One of the first things I'd noticed when I got the car was the degree of rewiring that it had undergone with many loose wires and extraneous relays lying around. I decide to download the schematics from www.hmaservice.com and do a careful re building of the engine electrical system. While doing this, I found a loose wire in the engine compartment fuse box that had been cut and rerouted. This single wire was the signal from the ecm to the ecu relay that controlled the timing of fuel from the nozzles. It had been rerouted to get power ddirectly from the ignition lock. I restored this connection and found that my engine would crank but no longer start. In other words, the part of the computer responsible for fuel management was not functional. The onlyy way to find out why was to have the car scanned.

To my surprise, the tech who scanned it said there was no response from the computer (ecm) and that he couldn't access it. We were both puzzled and had to get down to the innards. We finally found the answer at the ignition lock. There is a small antenna in the ring arround the ignition lock that activates the chip in the key and then transmits the code released from the key into the immobilizer chip in the ecm. If the code corresponds to the ecm programming, the immobilizer releases the fuel management and/or ignition systems and permits the car to start. This antenna was completely missing from my car.

Without it there was no way the ecm could give the signsl to the nozzles to release fuel and start the car so some smart rewire simply cut the wire and got the signal directly from the ignition. Unfortunately in doing this the car no longer had access to signals from the throttle, crank, MAP and MAF sensors all of which are important in helping the ecm calculate efficient utility of fuel and ensure smooth output of power.

I am now waiting for him to buy the antenna and fix it. Hopefully, this will solve the problem. Will keep u updated.

I am going through similar problem and need help. My throttle does not pick fast, when ever i slow down or when you want to fire the first time, it will delay only to later pick up fast. Please what do I do?