Loss of HP

**black plague815** · 07-31-2011

I have a 2000 gp gtp and it seems like Im losing power when it gets to normal temp. no overheating, No SES light, Ive changed my plugs and wires 3 times hoping this was it, new MAF, everything looks good. any suggestions?

**thegipper** · 07-31-2011

Does it only lose power after its warmed up? My 02 gt was losing power and it was a clogged cat. Once I replaced it, car never ran so good. You can remove the 02 sensor before the cat and take it for a drive with it out, and if it runs better then you know you have a clogged cat.

I would try that...

**black plague815** · 07-31-2011

Originally Posted by thegipper

Does it only lose power after its warmed up? My 02 gt was losing power and it was a clogged cat. Once I replaced it, car never ran so good. You can remove the 02 sensor before the cat and take it for a drive with it out, and if it runs better then you know you have a clogged cat.

I would try that...

I dont have a cat, just straight pipe without u-bend and zzp emulator

**black plague815** · 07-31-2011

I mean it runs like it is supposed to for the first 15 min, but it seems like it loses more when I leave the car running in place for too long.

**thegipper** · 07-31-2011

Any codes?

**black plague815** · 07-31-2011

Originally Posted by thegipper

Any codes?

No ses like I said above, so guessing no codes

**thegipper** · 07-31-2011

Is the power loss very noticeable? or is it barely losing power?

**thegipper** · 07-31-2011

Yeah I wish I could help more but I can't think of anything off the top of my head. I can tell you that "Theothernick" a member on this site who is on frequently is a mechanic and really knows his ****. If you haven't solved it ask him and he might be able to help ya.

He's been like 97% correct in diagnosing problems with my car. Let us know what it turns out to be !

**Tuner-Extraordinaire** · 07-31-2011

Probably reverting to low octane table.

What grade fuel ya runnin?

**black plague815** · 07-31-2011

I dont use anything but 93

**TheOtherNick** · 07-31-2011

Fuel pump could be getting weak after the car has ran for a while.

**MoarkatsINmuhtrailer** · 07-31-2011

get it pressure tested to see if its putting out what it should.

**black plague815** · 07-31-2011

Originally Posted by 99PGPGT

get it pressure tested to see if its putting out what it should.

Do these gp's have a test port on them?

**TheOtherNick** · 07-31-2011

Yup right on the front of the fuel rail.

**black plague815** · 07-31-2011

The guy that did my exuast said my fuel pump could be going because it had that loud hum, but I didnt pay any attention to it because I heard they all make that noise.