My car was running preety decent but i needed it to pass smog so i took it to a shop they said it was running to lean, so they "fixed" got it back and when i start it it sputters and cant idle for crap i put it in reverse and it died on me twice trying to take it home from the shop. it now needs to be warm befor i can start driving it. should i go tell them to put it back or does this mean they fixed one thing but something else is wrong now that needs to be fixed? also how do u change if it runs rich or lean or just right?

 

about a million conditions determine if a car runs rich or lean

take it back to them and have them fix what they should have initially fixed. after all, it's your money.

 

yeah thats what im going to do but i wasnt sure if they "fixed" the problem but it made it so there was other problems...if that makes any sense.

 

Sounds like the IAC motor is acting up possibly...is it connected?

Stumbling at idle, especially when cold, can also be a stuck open EGR valve...

 

How do u fix the EGR valve?

also how do i know if the IAC and sorry but what is that?

 

IAC valve is a valve mounted near the throttlebody that allows air to bypass the throttlebody during idle and sharp decelerations, etc. A non-operating valve will cause a car to stall on sudden deceleration or braking, and not idle until it's warmed up, and it will usually idle low after this. It looks like a cylinder and will probably only have a 2-4 wire hookup.

The EGR valve.....well, the "industry" answer is you don't fix it, you replace it. But depending on the type of your valve, it is POSSIBLE to repair them...if you have a vacuum EGR valve, you can spray lots of penetrating oil on the shaft after youve removed it and put it in a vise, and attempt to move the plunger in and out. Wiggle it, tap it with a hammer, spray more penetrating oil. Repeat until it begins to budge, then keep working the valve plunger up and down until it moves freely. I did this on my Probe and it took about an hour but saved me well over $100.

If you have a digital EGR valve....well unfortunately you're pretty much out of luck. Chances are, you'd end up breaking it trying to fix it.