[jahwarrior007]

Good day to all...question...my '99 Forester has the check engine light on and haven't had the time to check with the code reader, hope to get to it this week. Anyway, been reading up on the MPG and exhaust forums; I am getting, probably 15-17 MGP. So after reading up, I thought I'd check the catalytic converter. Not sure if I could physically see if it was ok or not, but I was surprised to see that the previous owner had put a hole:surprise: through the comb material. I read that some were saying, running without the converter is asking for burnt valve or other major issues. Thoughts ???

 

[rustfarmer]

I believe the first O2 sensor (ahead of the cat) reads and signals to the ECU for fuel mix, while the second O2 sensor (after the cat) monitors the cat's performance and set the check engine light if the cat is not working properly. My 98 Forester had the cat completely removed by the prior owner and although the check engine light is always on, it runs fine and gets normal mileage. I don't like this, because if something else fails I won't know it unless I read the codes every few weeks just to be sure, but I don't believe engine is affected. Best idea is install new converter and check the muffler for being clogged. Aftermarket universal converters are about $100.