TNT02z28

Have a 1996 Camaro V6 3800. Its kicking a code for a cylinder 6 misfire. It has new plugs and wires. One thing I noticed was the number 6 plug smelled like gas. I'm thinking it could be a bad o2 sensor. Is there any way to tell if the o2 is bad without buying a new one? I have a new scan tool with live data display is there a way to tell what it could be by using it?

Evolution223

I think you have a bad coil pack

TNT02z28

I got the p0306 code fixed and now it went to a p0300 code which is just a random misfire. I also forgot to mention that when the car starts it runs really rich. I checked the fuel pressure and its running around 45psi.

lukel03

Sounds like this.

Injuneer

Using your scan tool, check:

-coolant temp sensor reading on cold start. Faulty low temp indication can cause it to use too much cold start enrichment

-check long term fuel corrections for bank 1 and bank 2. You want 0% correction (128 block learn multiplier) or within +/- 5%. If its adding a lot of fuel (positive %, greater than 10%), and you feel its running rich, it may be a faulty O2 sensor, faulty wiring, exhaust leaks before the O2 sensor, or simply from the misfires. All those can cause a "false lean" condition, and cause the PCM to add fuel the engine doesn't need.

You indicate the fuel pressure is 45psi. Under what conditions? A complete pressure check:

-turn key to on, without starting the engine. Turn key off. Fuel pressure after initial prime should be at least 40psi. When pump shuts off, pressure should not bleed down rapidly.

-start engine, pull vacuum compensation line off fuel pressure regulator Hold finger over line to prevent vacuum leak. Correct fuel pressure is 43.5psi. GM accepts readings in the range of 41-47psi. While you have the vacuum line off, check for wet fuel or heavy fuel odor in the line. A leaking FPR will cause a rich condition.

-reattach vacuum line to FPR. Pressure should drop proportional to intake manifold vacuum. An 8psi drop from the "no vacuum" reading would be normal with a stock cam.

-If you suspect its running out of fuel at high engine loads (doesn't appear to be the problem here), tape the pressure gauge to the outside of the windshield, take it out on the road, WOT/max rpm the fuel pressure should not drop below 40psi.

Joseph Mack

I've got a 99 which I had the same problem. mine was a number of things. plugs were not correct gap, should be 0.060, make sure none of the wires are to close to the exhaust manifold, 3.8 had a lot of problems with heat build up in that rear corner where number six is. as far as it running rich, run the car for a few minutes and shut it off. pull the vacuum line off the fuel pressure regulator. If there's fuel present in the line it means the regulator went bad. common prob. The FPR is located right on the fuel rail drivers side in the back under the cowl. easiest way to swap it out is to pull the fuel rail from the intake and snake it out to the front. you can get away with leaving it hooked to the main fuel lines though. The FPR is held in with a internal snap ring. Good Luck! It's a real pain in the you know what.