that test does not sound by the book to me lol putting in revers and stepping on gas is not a valid test for a misfire. if you had a clogged injector you would have that cylinder leaner then the others. its unlikely that all injectors got clogged as once. If the plugs look fine my money would be on a vacuum leak.

 

He was listening for the misfire. He checked for a vacuum leak and there was none. I am going to run Lucas Oil Injector cleaner for a while to see if it helps.

 

Random misfires is usually fuel related, but not a specific injector since that would be a more specific misfire.

Get a fuel pressure test done.

Change your fuel filter, pull the vacuum line off the fuel pressure regulator and see if it is wet or smells like fuel. If it is you might need to replace that.

 

Thank you for the advice. I will try to get it done tonight.

Update: I went and bought an AC Delco fuel filter. I hope I can find a tech to change it for me tonight.

 

Put the car on the lift this afternoon and come to find out, the fuel filter is brand new. So after eliminating a vacuum leak, bad plugs, and bad fuel filter, that leads me to believe it is the injectors. The fuel pressure regulator was also checked and is pristine as the tech described it. I put some injector cleaner into 3/4 tank of gas on Wednesday. On my next fill up, I will put Techron in the tank. I hope that will also help the low idle while in drive (550-600 RPM).

 

Yesterday I put Techron into my tank. How long til I notice that it is working? I am hoping that it eorjs and clears my P0300 code. My fuel filter, spark plugs are brand new. There are no vacuum leaks. I am also thinking that the dirty injectors are causing my low idle in drive.

 

P0300 can be set by a air/fuel delivery problem (vacuum leak, dirty injectors, etc), but a problem with the ignition system is a more common cause. I would double check the plugs, wires and coil. If nothing is found there I'd check the EGR valve to make sure it is not being held open by a build up of carbon deposits. If it checks out okay then I would start searching for a vacuum leak and testing injectors.

 

I am still new to my car. I am learning more about it as I try to correct this problem. Where is the EGR valve on the 3.4? I had the plugs and wires checked last week. They were brand new. no vacuum leaks were detected, that is why I am seeking to clean the injectors with the Techron. I am wondering how long it takes for the Techron to kick in. I will check the EGR valve....wherever it is.

 

As for how long it's going to take for the fuel system cleaner to work? Forever as if it were an injector problem it wouldn't be a p300 code. Put 1000 miles on it and then have the car professionally checked out.

 

Check the FPR, I agree a p0300 wouldn't be one specific injector, that would be a p0301-p0306 code.

Fuel Pressure Regulator Replacement- 3.4L And 3.1L V6 Engines