Service Engine Light On

[smoke35]

I had the NWP spacers and NGK Iridium plugs installed last Saturday (10/17). The car was running great. The kit gave the car some nice gains in torque. Anyway, I had also asked my mechanic to look for a rattle that has been driving me nuts for the past couple of months. Unfortunately, they were not able to find it. So today, I took the car to my mechanic and together we were able to locate the rattle. It was a small plate on the exhaust right before the header connects to the y pipe. In addition, they also noticed a small exhaust leak on my y pipe. It looked like a spot was missed during welding. So they welded the y pipe for me as well. I had a nice peaceful drive home, no rattles, no exhaust leak, no problems. A few hours later, I had to run out and all of sudden my check engine light came on. I also noticed that the engine temp gauge was slightly higher than normal (but still below half way). I plan on dropping the car off sometime next week, but I was wondering if anyone had a similar experience pertaining to either the Racingline y pipe or NWP spacers. Any information would be greatly appreciated.

[Ampli]

Can you extract your ses code with the pedal method?? It will help you to find what is going on!

[smoke35]

Originally Posted by Ampli

Can you extract your ses code with the pedal method?? It will help you to find what is going on!

Stopped at my mechanic. Code is P2A00.

Condition:
The output voltage computed by ECM from the
A/F sensor 1 signal is shifted to the lean side
for a specified period.

Possible Causes:
-Air fuel ratio (A/F) sensor 1
-Air fuel ratio (A/F) sensor 1 heater
-Fuel pressure
-Fuel injector
-Intake air leaks

My mechanic indicated that the car could still be relearning. Possible contributing factors: today was very humid for the first time in a couple of weeks, repaired air leak in y pipe. They told me to drive the car for weekend and see if the light goes off, and if not to bring it back.

[cookaroo]

Use the pedal technique to clear the code and see if it comes back up.

[Leathe of Heaven]

Yup. If it comes back then it's most likely an air leak.

[smoke35]

Originally Posted by cookaroo

Use the pedal technique to clear the code and see if it comes back up.

You're referring to the air volume relearning procedure, correct?

[cookaroo]

No, refer to this. May take you a few tries but it works.

http://www.nissanclub.com/forums/200...ses-light.html

[smoke35]

I used the procedure to reset Check Engine/SES light, but the light came back on again after an hour. I also noticed that before it came on, it blinked on & off very quickly about a dozen times.

[cookaroo]

Alright, well you can use the procedure again to get the code and call your local Nissan service dept to figure out what it is or I believe it's autozone that will read it for free if there is one around your area. Then go from there.

[smoke35]

I already have the code. See 3rd post in this thread.

[Juman]

It never hurts to check that it is the same code. You'd be surprised some times.

[smoke35]

I will recheck the code tonight.

I contacted Aaron from NWP and here is his response:

First, you mentioned your coolant temp needle is slightly higher than before. This gauge is pretty inaccurate and as long as the needle stays close to the middle, you are fine. I’ve seen the needle move slightly and the actual coolant temp stayed exactly the same. I’ve also seen the needle sitting perfectly in the middle from 160-230 degrees! That’s a pretty big range without the slightest movement from the needle. So unless your needle is past halfway, I wouldn’t worry. But check to make sure your radiator is full and that you have coolant in your overflow tank as well. Just to be safe. Also, I should bring out that the NWP Thermal Intake Spacers will not affect coolant temperature at all. It’s the intake manifold temperatures that are so drastically reduced.

Since you didn’t have a code after the Spacer install, that tells me you more than likely do not have an intake leak. But check for a leak just to be sure. With the engine idling, listen carefully to several spots near each spacer. You should not hear a distinct hiss. If you do hear a hiss, try to find out exactly where it’s coming from.

Also, that code that you gave me point right at the 02 sensor on Bank 1, which is exactly where they removed the heat shield, right? Inspect the wires carefully to make sure they didn’t get frayed or cut while they were removing this heat shield. That shield can be very sharp and I’ve seen SEVERAL cases where the insulation on the wires got cut back allowing them to ground or short.

Also, if your car is idling smoothly, then more than likely you do not have an intake leak. But if your idle bounces up and down, then check carefully for leaks.

Also, my guess is that you fuel pressure and injectors are still in good shape. To start, look closely at that particular o2 sensor. I am guessing that the sensor itself is bad or there is faulty wiring. Damaged wiring on this o2 sensor is much more common than some may think. It’s because it’s in a very cramped area. Also, if you still have an exhaust leak nearby that o2 sensor, it could cause the signal to be out of spec.

If the o2 sensor wiring is in good condition after checking carefully for proper continuity, then install a known good sensor to see if the code goes away.

[smoke35]

I rechecked the SES code and it's the same as before (P2A00).

[smoke35]

Since the last reset, I drove to work (~20 min) and no SES light (that includes no blinking).

[smoke35]

It turned out to be something really stupid. The heat plate they removed was held on by 3 rivets which were popped off leaving 3 small holes in the pipe right near the 2nd O2 sensor. Wholes welded shut, problem solved. My mechanic apologized his worker not catching the problem when he removed the plate.