Tune out P0303????

**rickisrad** · 05-18-2018

Someone I know is trying to tune out code P0303 misfire cylinder 3.

It is a guys from work 2004 GT. He is having issues passing emission testing since the light is on. It has(d) the random misfire and knock sensor circuit codes that were able to be deleted. For some reason I can not find the specific cylinder codes to delete (disable ses light). Is there a way to do this?? Thanks

**wstefan20** · 05-18-2018

90% sure there's a way to do it with hp tuners, but why not just fix the misfire...?

**rickisrad** · 05-18-2018

I have HPT but do not see that code In the list. Weird. He’s not going to fix it because he’s a cheap ass. I was going to throw one of my spare injectors in there to see if it helped him but my supercharged injectors are different from his NA. Someone put plugs and wires in it before he bought it but cross threaded the #3 plug. I unplugged the #3 injector and no change in idle. So I am thinking it is an injector. Tuning the codes out is temporary just to get his plates and buy time for him to fix it.

**mguzzo** · 05-18-2018

that diagnostic code isn't visible in DHP either

**Iceman6669** · 05-18-2018

If you tune out the P0300 code, sometimes it also disabled all the misfire codes as well.

**rickisrad** · 05-19-2018

Yeah I tuned out the P0300 and for some reason that and the P0303 was still showing as active codes in the HPT scanner. It didn’t show on the echeck code checker though. So the car “passed” the test.

**mguzzo** · 05-19-2018

as I like to say, "if it don't set the light, it must be all right."

**BillBoost37** · 05-22-2018

I do know that you can turn off P0300 and all the cylinders will still show up.

I just pulled up HPT and was able to turn P0300 to no report as well as P0301-06 for each cylinder on an 02. Looked at 04 and it's sure as heck missing. That's odd.