Here's whats going on and I am getting tired of it. If I don't figure it out I'm going to take it to nissan but really don't want to.

My check engine light will flash after 30 minutes of driving and my car will run rich with a big lag in acceleration and I will get a thumping sound and a funky smell. If I reset the ECU and do the Throttle body Relearn, it goes a way for a little bit then comes right back. Sometimes the problem will fix itself but the Check Engine Light will stay on. Then after a couple of days of driving it will flash and do the same thing over again.

While driving yesterday, I'd noticed that it gets really hot around the side of my shifter between the driver seat and passenger seat.

I took it to AutoZone a few months back and they did the diag. test and said it was my Mass Air Flow Sensor. I got that replaced and resetted the ECU and it was fine for a couple of days. Then the problem comes back. Can this be my O2 sensor or Catalytic converter.

Please Help!!!!

 

How many miles on the car

 

About 89K now.

 

Oh yeah.. before the problem starts, I usually get the thumping sound first, then the smell and then I will lose power. Car still accelerates but no power behind it and the exhaust sounds weird.

 

id take it to nissan and ahve the codes read there.
that thump sounds like a backfire./misfire issue.

 

Should I check my spark plug. Can that cause the misfire. Why does it go away when I reset the ECU? Thats whats throwing me off. Also, when I took it to AutoZone for the diag. Test only the MAF sensor code came up. Nothing else.

 

yep, pull em all and look for oil in the plug tubes too, if you have it, it needs new valve covers, not just the gaskets but the whole thing.. very common, espec at 90k miles. PLug issues wouldnt throw codes either... maybe the general misfire code, but still, you can have torched plugs w no codes and terrible driveability..

are they the stock plugs still?
NEVER fall for the platinum only need to be chenged at 100k miles... mine were TOAST at 50k miles. I change them every year now.

 

just a thought, not saying its your issue,

for that....we would need more info from you, and then could give you some better ideas to search for etc.

 

NO, these are not stock plugs. Replaced them with NGK plugs around 60K. I did noticed oil on one of them. Just dip some paper towels in it and cleaned out the oil. After the change, car ran perfect with not issues. But I'll check them again today after work. It might not be the plug cause when I reset the ECU its fine.

 

I'd still take it to Nissan not auto zone, they have general codes, Nissan can give u a better idea even just with a scanner.

 

yep, cuz as soon as you started the car, they were full of oil again. Its the tube seal to the valve cover.. just a crappy design i guess, tons of threads to search on that.

 

I think I might just do that.

 

Also sounds like it could be a partially clogged cat. It would smell funny too.

 

My first guess as well. Either that or a rat crawled into your exhaust.

 

[QUOTE=03350ZVA;9308839]NO, these are not stock plugs. Replaced them with NGK plugs around 60K. I did noticed oil on one of them. Just dip some paper towels in it and cleaned out the oil. After the change, car ran perfect with not issues. But I'll check them again today after work. It might not be the plug cause when I reset the ECU its fine.

Ok.. Took it to Nissan. Got it diagnose. Turns out it was a couple of things causing the issue.

1) Driver Side Valve Cover has a leaked. Oil was leaking into the spark plug. Killed one Coil. Causing the misfire.

2) Kinetic V+ manifold had a small Vacuum leak due to over tighten the screw.

Waiting for my new Kinetic V+ to come in. Will let you know if the diagnoses was right. Good thing is, since the Master Tech at Nissan was doing it on the side, he told me to bring the car back once my Manifold comes in so he can finish the job. Would install it myself, but since I'd paid for the service already, might as well take it back to him....

Thanks for all the input.

 

got my New Manifold. Installed it. No vacuum leak. The problem is still there. Now they are telling me its the Fuel Injector. Replaced that. Still have problems. Now they are saying it might be a leak in my header and a bad Bank 2 O2 sensor. Going to lift the car up myself and check the O2 sensor. I think it just might be the O2 sensor from the begining. They showed me the reading and the right side reading was good, but no reading for the left side. They said it was the bank 2 sensor.

It's getting expensive and frustrating........ Oh yeah, before I brought it to them, I never had a gas smell. When they brought it back, I'd noticed the gas smell. Now they are saying I have an exhaust leak. Can the bad O2 sensor cause a gas smell...

 

A bad O2 sensor upsets the ecu's mixture control. The misfire lets unburned fuel get into the catalytic converter. Some fuel burns in the converter, causing the floor to get really hot. What doesn't burn causes the gas smell.

 

Yeah, it was the O2 sensor. Replaced it this weekend but car is still not fixed. Gets this knocking sound still and check engine light still comes on. Sounds like the problem is causing the knock sensor to come on and the car is trying to run in safe mode or something. If there is such a thing. Trying to excelerate, car moves but barely. Feels something like a vacuum leak.

What can it be...........