I have a 96 monte carlo. When I changed the rear plugs and wires I got a check engine light. The car runs pretty solid. When stopping at a light and slowing down to about 3 miles in hour. The car shakes. More like a forward/back motion shake. Mainly the engine light stays on for a while but if I drive alot without stopping for a long period of time then the check engine light goes off... I changed the plugs with NGK 0.60 gap and new wires both front and back with Napa 7mm. I also did all the coils. But I'm still getting the light on and off.
I was told it has to be one of the fuel injectors. The engine code is 300 Faulty plugs, Wires, Low fuel pressure, Vacuum leak, Coils. What do you guys think? Please any information would be a great help!!!!!!!!

Dan.

 

MAYBE TRY THE 02 SENSOR OR A CARBON CLEANING USING THE DRIP KIT FROM LIKE A CHANGE A LUBE PLACE. COST ABOUT $60 BUT REALLY WILL UP THE SMOTHNESS AND PERFORMANCE.

 

The problem your describing sounds like a misfire to me. But that would throw a code. If it is throwing a misfire code it could be a fuel injector. Either replace the faulty injector and see what happens, or if your strapped for cash, you can switch the injectors around and see if the misfire occurs on a diffent cylinder. Then you have positively identified the problem as a bad injector. But the latter method of diagnosing that problem can be time consuming.

 

I had the same problem and took it to a local Lube center. They cleaned the fuel injectors, still the same. I had replaced all the sparkplugs and wiring. I was ready to replace all the coils on my LS1 motor, $$$. A friend suggested I take it to the dealer, they have stronger injector cleaners. I did and SUCCESS!

 

you may have just gotten a bad plug, it happens from time to time. just because a part is new doesnt mean it isnt bad. also, id use ac-delco plugs personally because thats what they come with. ac-delco for gm, motorcraft for ford, and whatever cheap crap for a dodge because its just going to break anyways