My "check engine soon" light came on recently. I brought the car to the dealership because I had the extended warranty on it. It is a 2000 GXE Maxima with 65,000 miles. They told me it was the coils which they subsequently all replaced. However while I was there I also told them that the car was running rough, not accelerating like it used to. EX. At 40 MPH when flooring it the car's rpms jump up (engine revs loud) but the car doesn't jump with it but accelerates VER SLOWLY or NOT AT ALL, the same happens at 80 mph. There is no way I could make a quick pass on the highway between trucks like the way I use to. The dealership initially stated it was a transmission issue. Long story short, the car was test driven and stated it needed a complete fuel system flush (inc. replacement of the fuel filter). After a $200 bill, I drove the car again and the problem appears to be better but the car just doesn't accelerate like it used to. Could it be bad gas or something else. The dealership (the guy who test drove it) swore to me that it was a fuel issue. This is not a subtle change in the way my car performs but drastic enough that it is ticking me off because I can't find any answers.

 

Does it do it in neutral or just in gear? Sounds like a tranny problem to me, but it could be more than one problem your having? If your getting RPM's but not going anywhere it sounds like the tranny is slipping. Take it to another Dealer to get second opinion.

 

Repleace the MAF sensor.

 

It is 120% the MAF.

 

Yeah i think im having the same problem my 2002 auto keeps on loosing to my freinds 99 5 speed which i should win..... when i floor it from 40 goes really slow, maybe tranny slipping.