I have a 2002 Accord EX I bought from my mother for my kids to drive. It only has 130000 miles on it and overall seems in good shape. Recently the alternator died and my wife's uncle helped me change it. After it was replaced, the car exhibits a couple of odd symptoms.
1. If left sitting idling, it will begin to rev the engine up a down
2. the Check engine light will come on (not sure of the code yet)
3. the TCS light comes on

I took it to a brakeshop to get the brakes replaced and asked about it and he said he noticed the Power steering pump was working really hard and thought it might be related. I would prefer not to scrap the car, but I don't want to put too much money into it. Any ideas?

 

You could go to a place like AutoZone and have them check it first for proper battery and alternator performance. I know the alternator is new but some times new ones are lemons. They could also check the CEL while you're there. I have a 2000 Accord SE. The symptoms may not all be related but then again they might. Idling up and down can be the throttle body needs to be cleaned and/or the Idle air control valve. It could also be that a vacuum hose was unintentionally loosened when the alternator was replaced. See Scotty Kilmer's Youtube video "How to fix a car that idles poorly" and "Finding engine vacuum leaks with a cigar". For the idle air control valve try "How To Solve Honda Idle Problems - EricTheCarGuy". For the power steering pump you can try Scotty Kilmer's trick with Seafoam TransTune "Fix sticking power steering". Good luck.

 

It's possible when replacing the alternator that somehow a vacuum hose got touched and it may have ruptured. It would be best to take your car back to that mechanic and have him take another look at it.

 

Thanks for the suggests. I'll check it out

 

Pull and post the code

 

I haven't had a chance to take it to the mechanic yet, but the code is P0505

 

That's the generic code for the IACv but I'm not sure if that's exactly means on the 02 Accord. (I have the same car with 151k miles)

 

Again, first check all vacuum lines before trying to replace anything. That's a generic code for iacv function but it could just be a vacuum hose.

 

Thanks all for your help. It ended up being the IAC valve that needed replacing.