'02V70XC-Failing ignition coils-catalytic converter the caus

[xcincalgary]

My non-dealer Volvo repair specialist has had my car for far too many days this month. It's an '02 V70XC with 110K miles on it. I started out having to replace the transmission (which I had been putting off for nearly two years) and also the ECM. The symptom on the ignition side is poor idle, throttle response, check engine light periodically (goes off after time at constant speed on highway). Codes said that #1 coil was bad. Replaced that and now #4 is gone. Mechanic is stumped - says it may be related to a bad catalytic converter. Explanation was that a problematic converter can send signal and overload the coil. I don't want to replace the converter unccessisarily, but also don't wan to keep replacing coils.