First SES question
Allroy
05-14-2004, 04:10 PM
My 1998 Silverado 5.7 threw a Service Engine Soon light for the first time on the way to work the other morning. A buddy of mine threw his OBDII on it and it said "Right Bank Rich". He said it was an O2 Sensor malfunction or something and told me to try and run some injector cleaner in my tank. I did and the light went off after about 25 miles. Has anyone else ever had this problem? Does this mean that the problem has been solved or are my O2 sensors going bad? Thanks in advance.
Jeremy-WI
05-14-2004, 04:27 PM
It was probably a clogged injector or stuck poppet that caused the exhaust to be rich and the injector cleaner fixed that problem.
Levi(WA)
05-15-2004, 01:42 AM
My 98 did something like that just the other day, I started it up cold and it seemed to have a slight miss,as I drove to town (20 miles) the SES light came on and every few minutes it would start to flash on and off. When I got to the store I shut the engine off, when I returned to the truck and started it up it ran perfect and the SES light was off...very strange...:screwy:
broughy84
05-15-2004, 03:41 PM
A flashing SES light means the computer is sensing a misfire.
Levi(WA)
05-16-2004, 01:09 PM
Well it was misfiring so that answers that one...:lol2:
LastOne
05-16-2004, 07:28 PM
Regarding misfires on 5.7 Vortec's.
I have spent a lot of time and money trying to fix a misfire I am having. It turns out these engines have a problem with the valves sticking under certain conditions and are sensed as a misfire, either random P0300 or on one cyl. A top engine treatment ( SeaFoam ), and a quart of Marvel Mystery Oil have made it drivable again. Still not perfect but I am OK with it until it gets worse and I have to pull the heads.
I have spent a lot of time and money trying to fix a misfire I am having. It turns out these engines have a problem with the valves sticking under certain conditions and are sensed as a misfire, either random P0300 or on one cyl. A top engine treatment ( SeaFoam ), and a quart of Marvel Mystery Oil have made it drivable again. Still not perfect but I am OK with it until it gets worse and I have to pull the heads.
GMMerlin
05-16-2004, 07:36 PM
Regarding misfires on 5.7 Vortec's.
I have spent a lot of time and money trying to fix a misfire I am having. It turns out these engines have a problem with the valves sticking under certain conditions and are sensed as a misfire, either random P0300 or on one cyl. A top engine treatment ( SeaFoam ), and a quart of Marvel Mystery Oil have made it drivable again. Still not perfect but I am OK with it until it gets worse and I have to pull the heads.
Usually I find this condition under a load or cruising speeds.
A cold misfire or rough idle cold condition can be caused by sticking injector poppets.
I have spent a lot of time and money trying to fix a misfire I am having. It turns out these engines have a problem with the valves sticking under certain conditions and are sensed as a misfire, either random P0300 or on one cyl. A top engine treatment ( SeaFoam ), and a quart of Marvel Mystery Oil have made it drivable again. Still not perfect but I am OK with it until it gets worse and I have to pull the heads.
Usually I find this condition under a load or cruising speeds.
A cold misfire or rough idle cold condition can be caused by sticking injector poppets.
Automotive Network, Inc., Copyright ©2025