2000 Maxima running rough

[cpaw2112]

2000 Maxima, auto, 58k, original MAF & O2 sensors

problem started with rough running, intermitant engine power, shifting bad, problem slightly better when at full operating temp. replaced: plugs (Autolite Platinum), PCV, air filter. This didn't help. alternator went bad, after I replaced it, when I started the motor (cold start), the engine started fine but wouldn't rev above 1k - 1.5k until the engine warmed up. When driving, still had the same problems as before only worse.

Engine light came on, I then download code P1320 and replaced all 6 coils with Nissan parts and cleared the ECU.

Running inproved slighty but the starting and power problems still exist. Cold starts are worse to where the engine wants to choke for the first 10 secs.

After reading posts by NISTECH about the MAF, I'm thinking this may be the problem. While the engine was idling I uplugged the MAF and the engine cuts off. Is this normal?

Any suggestions?Can the MAF be easily tested?Now that the ECU has been cleared for a couple of days, could there be new stored codes on the ECU when there is no service engine light on?Should the 30 day old plugs be replaced since the coils are new?

[cpaw2112]

NISTECH, would you give me your opinion of this problem. I need some help. Thanks

[NISTECH]

Under hard accel it feels likke the trans has a very delayed shift or its slipping? If you say yes to this your maf is the problem. when you unplug it while running it will die,normal. how ever you should be able to restart it and see a difference from when it was plugged in. there will be a huge hesitation when you try to goose the throttle with it unplugged but it will rev through if you give it a sec. Being you say you have the original MAF I am 99.5% sure thats what your dealing with. Be sure you got to the dealer and have the ecm reflashed when you install this new maf or you may experiance some other run problems and burn up the cat and your new maf.

[cpaw2112]

Thanks for the response. Should I tell them specifically to replace the MAF and reflash the ECU? Or will they require an unnecessary diagnostic? Do you know about what this repair will cost?

[NISTECH]

Buy the MAF , about $120. Then take it and the car to the dealer and tell them the paper in the box says they need to reprogram it when it is installed. No diag.

[cpaw2112]

Could I replace this myself then drive 1 mile to the dealer to get the ECU flashed?Would this cause any problems?

[NISTECH]

yea you could do that. Shouldnt be a problem.

[cpaw2112]

MAF was exactly the problem.

There was a noticeable difference after having the ECU reprogrammed at the dealership. Bad thing was they charged my $128.00 to do it. Thanks NISTECH, couldn't have done it without you.

[NISTECH]

your welcome man ,anytime.