How do you know the cats are plugged, was an exhaust back pressure check done?
Do you have some kind of scanner to check O2 sensor operations ? Did the misfire on 3 come up after the tune up?
What's the P0157 code ?
Do you have some kind of scanner to check O2 sensor operations ? Did the misfire on 3 come up after the tune up?
What's the P0157 code ?