Badly missing
03-24-2011, 06:50 PM
#1
Teching In
Thread Starter
Join Date: Feb 2009
Location: Western Australia
Posts: 48
Likes: 0
Received 0 Likes
on
0 Posts
Badly missing The other day I filled up my car with fuel and took it to an exhaust shop to have new cats fitted and some other minor exhaust pipe mods done.
When I picked the car up and started to drive off it started to missfire badly like 1 or more leads were off. It would randomly come good and then get bad again. Its blowing out heaps of black unburnt fuel smoke which it never used to do.
The first thing i thought was they have stuffed my o2's since they moved them slightly (about 6 inches) so I took the car to my tuner who turned off the o2's in the tune which made no difference. If anything it made it even worse. I have changed my spark plugs also to no avail. The motor is a crate motor (l98/l76) with only 3,000kms on it so the leads are all near new.
So the only two things that were done on the day the problem started was new tank of fuel and exhaust work. They didn't take the headers off they just changed some flanges, put 2 new cats in and re-made some pipe for better ground clearance.
Any ideas what the hell is causing this? It gets so bad that the car feels like its gonna cut out sometimes. Could they have shorted something out when welding the exhaust?
When I picked the car up and started to drive off it started to missfire badly like 1 or more leads were off. It would randomly come good and then get bad again. Its blowing out heaps of black unburnt fuel smoke which it never used to do.
The first thing i thought was they have stuffed my o2's since they moved them slightly (about 6 inches) so I took the car to my tuner who turned off the o2's in the tune which made no difference. If anything it made it even worse. I have changed my spark plugs also to no avail. The motor is a crate motor (l98/l76) with only 3,000kms on it so the leads are all near new.
So the only two things that were done on the day the problem started was new tank of fuel and exhaust work. They didn't take the headers off they just changed some flanges, put 2 new cats in and re-made some pipe for better ground clearance.
Any ideas what the hell is causing this? It gets so bad that the car feels like its gonna cut out sometimes. Could they have shorted something out when welding the exhaust?
03-25-2011, 08:15 AM
#4
I was going to say check your plug wires. I have had the same issue intermittently when one was burn though. But i assume you probably would have seen it when changing your plugs
03-25-2011, 08:30 AM
#5
Teching In
Thread Starter
Join Date: Feb 2009
Location: Western Australia
Posts: 48
Likes: 0
Received 0 Likes
on
0 Posts
Thanks guys looks like it is actually the O2's. The exhaust shop has admitted to using non sensor safe sealant so are replacing them for me after they clean all that stuff out of the exhaust. Tuner reckons its running bad with them off in the tune cos the fuel tables are all over the place so once i put the new ones in and they are re-enabled it should be all good. fingers crossed