Have a 98 Ek hatch non v y7,
Cold start ups has a high idle at about 3k and warm start ups have a really low idle looks about + or - 200 rpm... Could it be that I only have one o2 sensor? It's str8 pipe from the header to the exhaust so I only have one o2 sensor. What else could it be? Maybe a vacuum leak?

 

Stock ecu?

 

CEL codes? Have you cleaned the IACV?

 

Pulled codes and only two came up. It said my airbags were out (I unplugged it) and the other said my secondary o2 sensor was out (like I said it's str8 pipe so no cat converter). But how do I clean the IACV?

 

Yeah everything is stock

 

The CEL does not indicate airbag system codes.

Removing the cat would throw the CEL cat code P0420, not a rear O2 sensor code. What is the exact rear O2 sensor code?

Click the IACV link in my signature.

Have you bled the cooling system?

 

Yes I have bled the cooling system.
I pulled the codes off of the obd2 scanner. Didn't have a CEL cat code

 

Had the same problem before. Cleaning iacv will probably solve it if you havent fix it yet. I also have 1 o2 sensor straight pipe and the only reason why it is giving you that cel code is because the other sensor is unplug. Clean TB and look for some vacuum leaks. I got mine fixed by changing my ecu. Since i had a mini me that was using an auto ecu to a manual car so i changed it yesterday and everything is runnin so smooth

 

Okay thanks. By the way I can't seem to find jumper plug anywhere... I'm converting my dash to 2000 so I'm currently working on the ac core underneath but I still haven't come across my jumper plug. It's missing

 

May i ask whats the whole reason of converting it to 2000?

 

automatic a/c controls....its a fad. Jumper harness is small and its tucked above the ecu in the passenger side kick panel.

 

Oh okay... Well i have a 97 cxhatch and i was planning to do that but my reason was i wanted a double din player in my cara and there is a way to install climate control without changing the dash but it will be using the same climate control as for 97 all you have to do is put the stock climate control where the cup holder at but since you wanted the control and everything then thats a best choice but more work heheh good luck though

 

Currently I did exactly what your explaining cause I have a 2000 climate control for my deck and I put my 98 ac bezel in the compartment. It takes a lot of adjustment letting you know ahead of time cause you might have to make brackets. But I wanna convert it so I can use the electronic climate. It's not too difficult if you just change the heater core to a 2000 than you can pretty much plug and play later with a few splicing here and there.

 

Any way thanks I cleaned the IACV and the idle problem is much better now. It isn't perfect but it's a lot more stable than it was befor

 

Thanks for the heads up... I was watching this video in youtube about it and it seems easier and plus i dont feel like taking it all apart haha thanks and im glad you fixed the problem