I have 01 GT 5 speed. The other week I put 87 octane into it and drove it, two things: when on the highway around 60 and throw it into 3rd and accelerate or during any hard acceleration I notice knocking 4000 and up rpms, second, when I start it or sometimes in traffic I notice bad exhaust smell, it smells like a race car or cart under acceleration.

Since I have only 24k miles on it, and since it was this way right out of dealer with 16k miles after service, I thought everything is alright. The smell thing was like this right from the dealer, the knocking is new. What do I do?

 

under warranty?if so take it back to the dealer

 

Not under warranty, gonna have to fix this myself. What do I check? Could it be spark plugs? I bet it never had plugs replaced. What else other than plugs?

 

throwing any codes?

 

No codes man, drives beutifully when not knocking.

 

check your spark plugs, one may be bad...my friend thought he was knocking but his 7th plug had gone bad

 

Try better fuel. I can't run most of the 87 octane fuels around here, and I have no mods that would require an increase in octane. Sometimes, the fuel quality is the culprit and not the engine.

 

Oh yea, Im running 91 now, though manual and FAQ on some sites say 87 should be just fine. When I run 91 I also get no exhaust smells, but with 87 it smells like Im running on dark site of detonation. Thus far I have two ideas, 1) check if I have a chip installed, 2) check plugs.. Its a new car, so it should be alright, this is rather surprising.

 

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