The knock sensor is there for the fine tuning of the engine, if the computer no longer sees a knock sensor signal it will no longer adjust the timing as incrementally as it would if the knock sensor could send a frequency to the computer when the engine vibrates as a result of the ping.

Instead it goes into a more fixed set of parameters, load and throttle equal this much timing advance. This over time can cause increased fuel consumption as well as take way longevity of some of the engine internal components.

The knock sensor is $100.00 on average, its worth replacing.

Justin

Without testing the Catalyst its all just a guess, you can try the o2 sensors and then some sort of treatment to the catalyst. But if the Catalyst doesn’t recover you will have spent some money to get no where.

You cant properly test a Cat without a gas analyzer and propane, and the knowledge of how to perform the test.

Hope this helps

Justin

When the check engine light comes on in your Subaru there is a code set, if the parts replaced don’t correlate to the codes set, the repairs will never keep the check engine light off in your Subaru. So if you have a PO420 Catalyst efficiency code and after market catalytic converters are installed most likely it wont fix the problem, there is a reason they are less and they do not last.

Also there are other things that can cause this situation, has it ever had a real analysis?

I don’t mean a code scan, a catalytic converter efficiency test with propane the only real test that should ever be done.

I don’t know the laws in your state but I would venture to guess no.

Justin

1. This week in 2 different ocassions I being driving normally and suddenly the engine goes to Neutral. Engine raves as you press the gas pedal but is just in neutral. Shifting to 2nd or 3rd doe4s nothing. I shift to 1st and then it moves again. I go to 1st, and it starts moving again. Go back to drive on both opportunities and it just being fine for days.

2. About 10-12 times a month the car won’t start when the key is inserted. I have to take it out, or change back and nofth between Neutral and Drive, until it finally goes ON. Someone told me thats normal in all Legacies, iis it right_?

Note> I hope I were in the States and not in Colombia where the only Subaru dealer is a fiasco!