P0300 code but car runs great
08-13-2012, 09:52 PM
#1
Teching In
Thread Starter
Join Date: Nov 2006
Posts: 14
Likes: 0
Received 0 Likes
on
0 Posts
P0300 code but car runs great Well my 99 SS Camaro's tach was acting up and the car was missing horribly. When hooked to a snap on diagnostic tool it said bad cam sensor and multiple misfires.
Swapped the Cam Position Sensor yesterday and the tach is reading/miss went away. The SES light has been on since I bought the car but it flashed for the first time yesterday when driving. I figured it needed a set of spark plugs and would go from there.
Today after pulling the plugs all of the odd cylinder plugs are a whitish tint but the even cylinders are black as can be. We checked all the coil pack connections and nothing appears to be wrong. Cleared the codes and drove it back home.
After driving 4-5 miles the SES light came on and started flashing again. The car runs great and doesn't appear to be down on power. I can't tell it missing at all.
Does anyone have any good ideas? Here are the mods on the car:
LT's
OR Y pipe
Magnaflow Catback
Ported MTI TB
MTI Lid
MSD Wires
Swapped the Cam Position Sensor yesterday and the tach is reading/miss went away. The SES light has been on since I bought the car but it flashed for the first time yesterday when driving. I figured it needed a set of spark plugs and would go from there.
Today after pulling the plugs all of the odd cylinder plugs are a whitish tint but the even cylinders are black as can be. We checked all the coil pack connections and nothing appears to be wrong. Cleared the codes and drove it back home.
After driving 4-5 miles the SES light came on and started flashing again. The car runs great and doesn't appear to be down on power. I can't tell it missing at all.
Does anyone have any good ideas? Here are the mods on the car:
LT's
OR Y pipe
Magnaflow Catback
Ported MTI TB
MTI Lid
MSD Wires
Last edited by bad01gt; 08-13-2012 at 10:19 PM.
08-14-2012, 05:48 PM
#4
my SES light will come on for a week or so, then it'll cut back off for about a month.....this has happened since i installed the longtubes......i've been through several sets of O2's of different makes, none affected the car in any different way, it's always ran strong.....i read in a thread that someone mentioned my issue might be a lazy O2, something about they have a heater element in them that sometimes doesn't warm up quick enough, but overall it still reads and functions fine.....sorry, i can't remember the details......
Last edited by jc98ss; 08-14-2012 at 05:55 PM.
08-14-2012, 06:08 PM
#5
headers wont cause a p0300 missfire code they usually just set off o2 codes. op what sounds like is happening is what happened to me. when you replace the cam sensor sometimes the new sensor isn't calibrated exactly like the old one and throws off the sync between the cam and crank sensor thus showing the condition of missfire to the pcm when in fact theres nothing wrong. you or a tech can verify this by hooking up a scan tool and watching the fuel trims to see hats going on. if it is false missfire you need to do a case relearn for the pcm which can only be done with hptuners or a tech2
