Cantankerous Subaru

The car in question is a 2003, Subaru, 4cyl, Outback, Wagon with over 100,000 miles on it. When stopping with the engine running the engine does not settle into idle but rather races at increased rpm requiring the driver to hold one foot on the brakes very firmly. In approximate succession the following has been done:

1) The dealer says it is normal and could not do anything to fix it.

2) A repair shop (Big O Tire) replaced the timing belt, replaced the spark plug wires, replaced the spark plugs, and replaced the valve cover gaskets to prevent engine oil from pooling around the plugs. They also said the catalytic converter was shot and probably causing the problem. The problem did not go away.

3) A muffler shop replaced the catalytic converter with no change in the idle problem but a much lighter pocket book.

The net result is an additional problem. After doing the above repairs and replacements the engine now stalls at highway speeds and refuses to start until it cools off. The idle problem is still there. This has been a good car but is not acting like a normal Subaru which normally are bullet proof.

You should have gotten a second opinion on the Catalytic converter causing the high idle as this is not likely. And since Big O didn’t do the Catalytic converter repair which they recommended, you have no recourse unless the muffler shop also said a new cat would fix the idle problem, in which case it would be on the muffler shops heads. Is the check engine light on? Any codes? Has anyone considered the idle air control valve which if bad will not throw a code?

The check engine lite is on and the code indicates a crappy catalytic converter; No one has considered the idle air control.

Thanks for your help