Help - Serious Performance Issue

[kwconnection]

I have a 2002 Altima 3.5 SE with 211000 km on it. Apprx. 10000k ago I noticed a loss of performance particularly at the high end (3500 RPM) so I had new plugs installed as I am sure they were due. The plugs that came out all looked good with no signs of fouling. This seemed to improve the issue some but then one of the Catalytic Convertors went and I had that replaced at a cost over over $1000. After this replacement I have a serious problem that when I am on the highway if I hit the peddle hard to pass someone it kicks down to a lower gear and revs to 4k but does not accelerate. I took it back to the shop that did the cat and they indicated I had a leak at the EVAC canistor Valve and that this is probably what caused the cat to fail They said I had error codes P0456 and P0021B2. I spent another $400 to diagnos and repair this - I now do not have any SES light but the performance issue remains.

The problem still exisits - Do I have a motor or transmission about to blow or is there another explanation?

[adidas2go]

take off your negative bettery terminal for 5 min. Then reconnect it. Sounds like the car is in its defensive safe mode. Get your radio unlock codes and **** before you do this tho.

[chow]

211 000km on a 5 year car?? hollyyy!

Other then that, dont have much to say.

[kwconnection]

Thanks - I had that suggestion from another site and tried it - no effect. Problem still exists..

[kwconnection]

All highway to - 100 km each way to work everyday.

[JLAUDIO85]

hey someone from k-w lol me too hahaumm sorry i got off topic...lol

[R1Wolf]

If it's down shifting but not accelerating, I would think you have transmission problems. But I've never owned an auto, so I could be wrong.

[shift_mikey]

Sounds like the mechanic may have run out of excuses and just pulled the light bulb so you don't see the service engine light.

In all seriousness, does the SES light turn on when first turning the key to the ON position (not running)?

What kind of mechanic did you bring it to? to a dealer? to a shade tree mechanic?

[kwconnection]

Yes the light comes on.

The Cat and second repair were done at Midas.

[shift_mikey]

It might not be cheap, but you could bring it to a nissan dealer, explain the problem, and tell them you just simply want them to run their computer diagnostics, and DO NOT REPAIR without an estimate and/or your approval