PontiacBonnevilleClub.com

So my car has a fairly irritating issue that only happens at running temperature (keep that in mind.) As from my early post a month or so ago I have cleaned my throttle body (twice) spark plugs are a year old, spark plug wires are two years old, ICM is two years old, fuel filter is six months old, and coil packs are 2 months old.

Well, I've got a hesitation that feels like a misfire but not as violent and I can't think of what it could be. When I hold on the gas trying to a comfortable speed the MIL light comes on and flashes like it would a misfire but when I cruise it goes off. When I pull the code it says misfire cylinder 6.

What could it be? Injector? Fuel Pump? I do need to replace the oil pressure sending unit but that shouldn't give the symptoms I'm having should it?

This isn't GXP related? Moved to 2000-2005.

I'd start with cheap stuff first. Run some fuel cleaner through your next tank, maybe the injector is gunked up.

You could also try moving around the plugs, wires, and coils to see if the misfire follows a certain part.

Injectors do fail, although it seems as though not as much now as earlier versions would. A fault in the electronic portion will not be helped by a bottle of cleaner in the tank. You have to pull the injectors and send them off.

The cars I have had the injectors pro cleaned and checked include a V-8, a V-6, two I-4's, and a boxer-4. One of the I-4's was extremely difficult to start, and had lost power.

The V-6 car showed the most noticeable difference in running performance, with a much more even power delivery. It would shudder/stumble, and set a check engine light.

Find companies online if you decide to go that route. The one I have used in the past is "WitchHunter Performance", and the service is awesome.
Whoever you use, make certain that they are capable of electronics diagnosis and do flow testing, both before and after cleaning.

My apologies with the mix up between the sub forums, and thank you for moving to the correct location.

Should I go a head and replace the injector or get it cleaned? And do you think it would fix the issue?

Hard to say if the injector is the problem or not.

First you'd have to sort out whether the issue is baing caused by an electronic, fuel, or mechanical problem.

In any case, I would not replace only one injector, if I really cared about a well-balanced power delivery. New injectors can be pricey, which is why I have traditionally had them cleaned and checked. For two of my cars which are identical models, I had 12 injectors to send, and marked all of them to see which wound up being the best. (Street car, "in progress" car, parts car) Two from my DD were electronically compromised. So I wound up with 10 good ones to use on the two cars (I-4 engines).

On the V-8 car I mentioned, I was *hoping* that injectors were the problem, but it turned out to be a soft camshaft lobe which had lost height, reducing the opening of the intake valve for the #5 cylinder. I checked valve lift after I had already done the injectors.

Since your car seems to suffer from the malady at running temperature, there could be other issues which could come into play, such as a head gasket, or intake manifold gasket.

So it would be best to have a diagnostic ran first? Its my everyday driver so I would prefer not to be without it for an extended period of time.