Losing power when going up hills, check engine light comes on and misfire on cylinder 1 & 2, catalytic converter code comes on too, I'm wondering what is causing the loss of power?


Asked by Apr 19, 2014 at 02:34 AM about the 1996 Subaru Legacy 4 Dr L Wagon

Question type: Maintenance & Repair

Could a failing catalytic converter cause an engine misfire and losing power, shaking, and stalling going up hill? I am wondering if the air/fuel mix injected into cylinders is off due to failed cat converter, and its causing misfire?

9 Answers


Stopped up cat will cause lose of power. But if it's the 2.2L or the 2.5L both plugs 1 & 2 come off of the same coil. You could have a bad coil or a fouled spark plug. Sometimes one fouled/bad spark plug will cause both plugs on one coil not to fire. This will also cause a lose of power. I feel that a coil or spark plug issue is more than likely your issue.

1 out of 1 people think this is helpful.

I agree with dandyoun. Sounds like you're misfiring under load. The most common cause of this is the ignition system breaking down. If you're due for a tune up do that and check the coil(s) as well. If one of the coils is failing the others are soon to follow. Replace them all. HTH. -Jim

2 out of 2 people think this is helpful.

Thanks for responding. I have already replaced spark plugs and ignition coil, but that didn't affect it. I've had this error code come up sporadically about the exhaust, code 420, and now the misfiring under load. Am wondering if misfiring and a failing exhaust system are connected? Would a bad cat converter contribute to misfiring, or does a misfiring issue cause a cat converter to fail?

4 out of 4 people think this is helpful.

My check engine light has never gone of since I bought my subaru BH5 neither is the power light. .dunno what the problem is. .

1 out of 1 people think this is helpful.

@Laichena I plug in the diagnosis and give out the cord, you get

1 out of 1 people think this is helpful.

Thank you so much. .will first do the service which I not done for long


How long can a turbo engine last?


Just been to a mechanic he asked me to do service


My 2004 outback has had the check engine light on for 9 years off and on, dealer did nothing. We've changed all the sparks several times, changed the coil pack, the wires, last changed oxygen sensor. Stalling on hills, flashing check engine. I'd love to get a few more years out of the car, but I can't trust it. I'm not sure I'd ever consider buying another Subaru.

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