Hello, I have a 1999 Chevy Blazer 4×4, 4.3l Vortec v6. Truck starts, and idle & rev are great til about 2500 rpm. Hooked up OBDII scanner, gave a “P0302” code which states “cylinder 2 misfire”. From what I found on Blazer Forum net, shows possible ignition problems. Went through and changed the distributor cap and rotor. Then the ignition coil, then the swapped plug wires from another to see if code moved to other cylinder. Changed spark plug. Added bottle of fuel injector cleaner, and sprayed the throttle body with proper cleaner as well. Still have same problems, idles/revs fine up to 2500 rpm. If I try to drive car around block, it bogs down at 5 mile hour, seems like it is flooding itself out, as it bogs when applying gas. Truck will not go above 5 mph. I was thinking possibly changing o2 sensors (truck has 2, one on driver side (upstream) and one by catalytic converter (downstream).
Have you considered the possibility of a plugged catalytic converter?
Thanks ProTech, I had one happen on a Honda accord I had, and when it went bad the catalytic converter would glow after couple minutes driving. I would say it is the factory converter on truck, cant I smack it with hammer few times to see if loosens up? Thank you for helping.
If it is the catalytic converter that is plugged, smacking it with a hammer can makes things worse, not better. You may dislodge a portion where it will turn and block totally the exhaust and then the truck won’t even run.
Ahh, ok, thank you. is there a way to test converter? Or will if glow if it is bad?
If really clogged it will end up glowing red if you drive the truck long enough. But if you have a temperature gun, that’s a good way to check it as well.
I will check on this asap – thank you protech!
You’re welcome! Glad to help.
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1 Comment on "1999 Chevrolet Blazer Misfire Cylinder Number 2"
2001 Blazer with overhead O/S temp and compass. When you start the engine the prndl and overhead lights light up as they should however, when the automatic headlamps come on, the lights go out and there are no dash lights. Checked all fuses including the ground fuses. Any ideas ? I know there is a control relay for the lights but wouldn’t that just be for the auto headlamps and running lights? Please help!
Sounds like the dimmer switch is bad. That is what controls those lights.