I have a 2000 SE 5sp with 191K miles. Idle is ok at first, then becomes rough after a couple of minutes, almost to point of stall.

When engine is cold, especially when outside temp is in 30F or less, the car bucks severely under light load.

Apart from that, it run fine, gives same gas milage as when it was new.

I ran a few cans of sea form through it and that helped, but cannot get it back to normal. IACV? Fuel filter? ECU? Which is most likely, I can start there.

 

Remove the ecu and check for the sta chip if is burned post pics the fixer might be able to help...


I think the cold weather is making all these issues appear ....wuz up with all these p0505 threads lately??? Everyone's ecm didn't burn in the same week

Even my car threw the code along with the p0420 after the engine bay cleanse a few days ago

 

To resolve your problem, try to answer the following questions:

• Is the CEL On/Off?
• When you check with ODBC reader, are there any codes?
• Any "incomplete" monitors?
• Does the car stall because of too much fuel, or because it does not have enough fuel? Do you smell gas when the idle becomes rough?
• What is the condition of your spark plugs?

 

You most likely have the same thing as me. I have the P0505 code. Check if your ECU is fried first. If not you can just Replace your Throttle position sensor and IACV. If it is frie, ur gonna have to replace it and get it re programmed and then replace the TPS and IACV. That's what I'm doing.

 

Any error codes? How did the problem start? Have you checked for intake vacuum leaks provided you don't have any error codes?

 

No codes thrown. No gas smells. Started at about 180K miles. Ran some Sea Foam thru system and that helped quite a bit, but cannot seem to get it to normal. Is it possible to have OBD info that does not show as a code display?

 

As I always say, (whether right or wrong) sounds like maf lol