OBD codes
huskym1025
02-23-2012, 12:07 PM
I have a 99 Chevy Tahoe, 5.7, 4WD. I had a P0303 and P0420 code. I changed my plugs and reset the codes. Is it safe to say that the misfire caused the P0420 code? Could my O2 sensor or cat still be bad? While on the highway, I would get a spudder when giving it gas, as soon as I let of the gas it would be ok. This was before I replaced the plugs. BTW, I was using AC 121 plugs and then switched to OEM AC plugs.
777stickman
02-24-2012, 10:21 AM
There are several things that can trigger the P0420 code and a misfire is one of them. Clear the codes and if it comes back then you have to look at other issues.
huskym1025
02-24-2012, 11:58 AM
There are several things that can trigger the P0420 code and a misfire is one of them. Clear the codes and if it comes back then you have to look at other issues.
I cleared the codes on Wednesday evening. So far now SES light.
I cleared the codes on Wednesday evening. So far now SES light.
tahoedriver
04-02-2012, 03:03 PM
One suggestion I can give is the poppets on the spider injectors become clogged with carbon deposits overtime, apparently their prone to failure. symptoms of a bad poppet are hard starting, misfire codes, rough idle, and loss of power. Hope this helps.
Automotive Network, Inc., Copyright ©2025