Random misfire 0300 code
02-13-2009, 09:34 PM
#1
Random misfire 0300 code MOD list:
QTP longtubes, QTP-y (no cats/rear O2s tuned out)
Borla Catback
UPD lid
FTRA (just installed it)
ASP Underdrive pulley
Fresh set of NGK TR55s gapped @ .048 (pulled and checked, no cracked insulators/look fine)
When driving at WOT/Shifts at WOT the car falls on its face for the 1-2, and 2-3 shift, SES light will come on for a few seconds then go out. The code is P0300 and there are two other codes for the downstream 02s I have deleted. I am wondering if its the front 02s and or the CPS? The car is ok if I roll onto the throttle through the gears no power shifting, just gradually going to WOT, however if I drop the hammer it runs like ****. I stay on top of maintenence and changed the fuel filter along with a seafoaming a few months ago. This problem just cropped up after install the ASP underdrive pulley and FTRA. I am tempted to replace the front 02s and wonder if I can use the rear 02s I no longer use?? Please throw some suggestions/advice out there.
Thank you,
Dave
QTP longtubes, QTP-y (no cats/rear O2s tuned out)
Borla Catback
UPD lid
FTRA (just installed it)
ASP Underdrive pulley
Fresh set of NGK TR55s gapped @ .048 (pulled and checked, no cracked insulators/look fine)
When driving at WOT/Shifts at WOT the car falls on its face for the 1-2, and 2-3 shift, SES light will come on for a few seconds then go out. The code is P0300 and there are two other codes for the downstream 02s I have deleted. I am wondering if its the front 02s and or the CPS? The car is ok if I roll onto the throttle through the gears no power shifting, just gradually going to WOT, however if I drop the hammer it runs like ****. I stay on top of maintenence and changed the fuel filter along with a seafoaming a few months ago. This problem just cropped up after install the ASP underdrive pulley and FTRA. I am tempted to replace the front 02s and wonder if I can use the rear 02s I no longer use?? Please throw some suggestions/advice out there.
Thank you,
Dave
02-14-2009, 07:04 AM
#2
Is your camshaft stock? If not, you need to go into the mosfire tables and "max out" all the values in there. This should keep your PCM from throwing that code. It is a common issue with an aftermarket cam. Otherwise, it will be hard to diagnose this problem over the web.
02-14-2009, 09:38 AM
#3
Thank you for the advise, however I am on the stock cam for the time being. The problem is just weird as it is intermittent. I can sometimes manage 1-2 WOT runs with no issues, then go to make a third pass and the car falls on its face sputtering and backfiring. You make an excellent point on the tuner, think I need to give my buddy a call and have him do some road datalogging.
