I have a 98 gt 5 speed. I keep getting a 0308 code. I have replaced the wire and the plug. It stays off a couple days then comes back. Any ideas on what I could try next before I ship it to the dealer?
Yep, that's what I'd do. If you continue to get the same code AFTER swapping the coil packs, get a new pair of upstream O2 sensors. Have you ever replaced the O2 sensors in your car? If you haven't its probably a good idea to do so anyways being that your car is 12 years old.
A persistent miss on a single cylinder isn't going to be O2 sensor related.
I agree with swapping the coil pack. If the problem stays on cylinder 8 you may have a fuel injector issue on that cylinder or a mechanical problem that's dropped compression very low (e.g. a burnt exhaust valve...) If the problem persists on 8 you might try swapping the injector with another cylinder. If the problem still remains on 8, do a compression test.
You may even have a goofy PCM if the coil driver for #8 is baffed...
I swapped the coils and the code stayed on cylinder 8. Besides swapping the injector, is there another way to test it without dealer equipment? How easy/hard is it to swap/change one as I have never done it?
The injectors are not too hard to remove. Remember to use new O-rings on the re-install.
If fighting a possible injector problem, consider an injector cleaning service such as injectorrx.com. I have had great luck with their service and it's much cheaper than buying new injectors.
This will give added piece of mind knowing that all 8 injectors are flowing about the same and have the correct spray pattern. For all practical purposes, once tested, the injectors are as good as new.
Another advantage is that you only have to remove the fuel rail once. Where as swapping injectors means there is at least two tear downs in your future.
The injectors are not too hard to remove. Remember to use new O-rings on the re-install.
If fighting a possible injector problem, consider an injector cleaning service such as injectorrx.com. I have had great luck with their service and it's much cheaper than buying new injectors.
This will give added piece of mind knowing that all 8 injectors are flowing about the same and have the correct spray pattern. For all practical purposes, once tested, the injectors are as good as new.
Another advantage is that you only have to remove the fuel rail once. Where as swapping injectors means there is at least two tear downs in your future.