01 Altima performance problem

[hassan385]

Hi everyone, I have a situation that i cannot figure out, hope someone can help.

I have on 01 Altima GXE, and have owned it for 4 months. 2 days ago on the highway, i tried to speed a little but the car won't go past 80mph. I mean i kept the gas pedal floored for like 15 secs and the car was progressing very slowly past 80 mph.

Then i tried to do the 0-60 and i got times of like 17 secs.

What could be wrong?

i had recently changed the dist rotor + cap and fuel filter. cleaned MAF sensor with the MAF Cleaner spray. I'm using full synthethic oil. Put new tires 2 weeks ago.

i also tried playing with the timing a little but it only makes difference in the initial pickup, as soon as i go past 78 mph, the car starts to feel restrictive.

The car drives perfect at low speeds < 65mph.

Any help would be appreciated.

Thanks.

[lucino128]

check your timing, maybe one of the cylinders was bad, do a compression test.

[itwillboost]

Did you try checking the spark plugs ignition etc. Also wat type of transmission are you running ?

[hassan385]

I have the timing set to 20 deg.

I'll do the compression test in a couple of days.

Thanks for the tip.

[hassan385]

I have the stock transmission.

And i don't understand what you mean by checking spark plug ignition.

If you mean whether spark plugs are sparking, then they all are and i changed them back in August i think and they are NGKs and i changed the spark plug wires (NGK NX series), distributor cap and rotor.

Can it be a restriction in the exhuast or something?I do get a P0420 code once in a while that goes away on its own.

[lucino128]

yea, it could be the CAT.

[hassan385]

Thanks again.

I made a video of the gauges just to show you what the car is doing. Someone might figure out what the problem is.

I did the vacuum test and the results were pointing towards worn rings or restricted exhuast. and someone suggested to remove the cat connection and run the test again to see if the cat is blocked. So i'll try to do that this weekend.

Anyway, please watch the video and see if anyone can figure out what's going on.

http://www.youtube.com/watch?v=ETttTV6aesw

thanks.

[hassan385]

Hi guys,

I finally figured out what the problem is, it is a restricted exhaust.

I removed the cat from the exhaust pipe and now the car is doing very well on the highway. It goes above 100 mph with no hesitation.

Check this video : http://www.youtube.com/watch?v=gnO0DLYynPc

now i need to figure out whether it is the cat or the muffler.

I'll keep you posted.

Thanks.

[hassan385]

It was actually the catalytic converter that was blocked.

Thanks for all your help guys.