2 videos included


2002 Maxima, had about 145,000 miles on it. SES was a P0037 (low voltage bank 1 rear O2) so that shouldn't affect peformance. I do have about 100 pounds or so of detailing stuff in the trunk and according to my GPS, the speedometer is 3 mph SLOW at 85.

Since replacing the offending O2, I now keep getting a P0420 code, which is bank 1 pre-cat and I would assume that if it is clogging that would be my problem.

No wheelspin:

http://www.youtube.com/watch?v=enVA49f0FFY

Whelspin and about 2 minutes after the first run

http://www.youtube.com/watch?v=-glzd6zAPsM

My car doesn't feel slow like it is a complete dog, just feels a touch less energetic. Sometimes it feels real strong though. No other codes, including pending codes. No idea when the plugs were changed, I bought the car with 113,000 miles on it. I am assuming if they hadn't been changed at some point my car would be running like absolute crap. Mileage is decent enough, about 19 city, 21-22 mixed (the light timing sucks hard here, pretty much stop at every single damn light). Haven't been on a long road trip in a while, which is where an exhaust restriction would most likely affect mileage.

 

Scott,
this seems very similar to when one of my cats got clogged up. Your overall preformance still seems to be pretty good, but when my cats got clogged I felt like the engine was less responsive. I felt like it would take more gas to make the car go faster or even increase the RPM.

 

still doing 0-60 in about 7 seconds

I agree with the cat comment

 

Have you tried a dyno? lol

 

I agree with the pre-cat being clogged. How does the car seem on a hill climb? Any smell of rotten eggs?

As for the plugs, since you really don't know the condition, there is some low hanging fruit items you could do. I would at least pull theplugs and check the condition. Also check the gap, that could cause some performance problems as well.

S

 

Every once in a while if I get on it I get the rotten egg smell, nothing regular though.

Honestly, if I am going to go to the trouble of checking plugs in a 5.5 gen, I'll just change them.

I've hit a few people up in the classifieds about their pre-cats, just waiting on responses and prices. I'd gut the damn things if it didn't mean I'd have to run O2 sims to pass emissions, the sims don't seem to be completely fool-proof and any codes mean I don't pass.

 

The front plugs can be sneaked a look upon very easily. That's a rotten code and tehre are many fixes & diagnostics. Could mean a MAF, could mean a dead pre-cat that was caused from a bad MAF, so fixing the pre-cat is a bandaid since the MAF is possibly the ultimate problem. Good luck.

Do you have access to any type of OBDII data logging software?

 

My Dad's mechanic has that type of equipment.

When I had the bad O2 replaced, the mechanic I used hooked up an OBDII reader far more advance than mine and said one bank was running a touch lean but it didn't appear enough to affect performance.

Wouldn't a bad MAF cause a large drop off in power beyond 2500 rpm? My car still pulls clean to redline.

 

Could be a slowly dying MAF. But yeah, sharp power drop off is a dead on indicator, you know that .

And yes, I saw your youtube vids.

 

The real issue Scott, is why you have this saved on your YouTube? You got some nasty lookin toes dude. No doubt...

http://www.youtube.com/watch?v=DA-eC...eature=channel

 

There was a thread on another board about posting stuff you can do that others can't. I thought I was the only one who could do that until I posted it on youtube and saw all the other videos.

 

So you'd agree my car doesn't seem to be pulling as hard as it should then, right?

I might check with the dealer about any ECU updates I might be missing.