I have a 2000 GLE automatic and I've been getting extremely bad gas mileage on the last 3 tanks.

I usually get around 240-260miles per tank with alot of highway driving but now i'm down to 175-190miles per tank.

Also, the engine does not feel like it has the power of 222hp as it should. My mom's 135hp camry feels faster than my car. When I rev it up, u hear the engine revving up but the car is still moving slow.

Then one day last week, i was just driving normally and the Service Engine Soon light came on. I went to autozone to pull the code and got PO 420. The guy told me it has to do with the catalytic converter but i highly doubt it.

After reading many threads on the forum, I think it's one of the three problems or all three not sure.

1. O2 sensor
2. MAF sensor
3. Ignition Coils.

Someone please tell me the symtoms of ignition coil problem because the ignition coils being the most expensive part to replace. I don't want to just start throwing parts in till problem is fixed.

Somebody help!!!!! Thanks in advance

PS: my car's only got 35k on the odo. My mom is bragging that her camry has 73k on it and never had a major problem like this. She said she'll never buy another nissan. I need to convince her that the maxima is a reliable car too!!!

 

HAve you changed all the filters and such? Also, try running some seafoam, maybe you got a little crud in there somewhere. Seafoam is available at Hi-Lo

 

2. MAF sensor
3. Ignition Coils.
is what i changed, when i had similar issues. everything is fine now. you can start by just cleaning the maf. does your car hesitate? any misfiring? when were the plugs last changed??ever cleaned the throttle body?

 

All the filters have been changed. I've done a full tune-up the summer. (pcv, air filter, spark plugs) it was at 29k

How do u run seafoams?

Zippin: no i don't think i ever cleaned the throttle body. And what do u mean by if my car hesitates. I just feel the car has no power. and sometimes when idling the engine rpm goes up and down till it bounces hard enough below 500rpm and shuts itself off.

 

you would know if it was your ignition coils because it would feel like you were hitting your abs all the time and the car is backfiring... it sux and mine are finally getting changed on monday!

 

if it is not backfiring / misfiring, it is most probably the MAF. you can get one for about 80 bucks from jerry rome, or dave. if i was you, i would look at the VIAS, then change the MAF ( which you will have to at some point).

 

mine just started missing at idle. You can feel the pulses out the exhaust really well if you put your hand over it and try to block it. with the Greddy every time it missed it sounds like my sub firing. Not so nice. I'm going to get them this week, and time for some new ngks. I don't think my maf has anything to do with it, but if you're seeing the same stuff I'd go for the coils. I had one replaced at like 60k, so i'm doing all 6. The rears suck with a strut tower brace.