Rough idle + check engine light

[DDKing13]

So I'm driving on the freeway, everything was fine. Then as soon as I exit the freeway and come to a stop, the engine started idling really awkwardly, and the check engine like came on. But as soon as I accelerate and start driving again, it's fine and the light turns off. But of course, as soon as it idles it does it all over again. Anybody have any idea what it is?

[roguetoaster]

Do the stomp test and report back with the code(s).

If I had to guess you have an air leak or a bad O2 sensor. The former causes the condition you described even when dead cold, the latter does not.

[DDKing13]

What exactly is the stomp test? Excuse my ignorance.

[DDKing13]

Rough idle + check engine light

Nvm, I should've googled first before asking. Lol

Will report back with codes.

EDIT: so the code it threw is 1222 I believe

[roguetoaster]

So, you can consult the code list here: http://www.verrill.com/car/e30_faultcodes.shtml

That will give you a general idea of the issue, then search this subforum for "1222." You shall find all the info you can stomach as I don't want to go into laundry list mode here.

[DDKing13]

After doing some searching, I can't seem to find anybody who has the exact same symptoms as my car, and all other threads have out of date links and not really any solutions posted.

Since there's such a long list of things it could be, i'm kind of overwhelmed and don't even know where to start. I sprayed starter fluid around my intake and headers to check for leaks, and didn't find anything. Anywhere else I should look for leaks? I bought a new intake boot, AFM, and stock air box to replace the cone filter setup the previous owner installed on the car. Also going to buy an O2 sensor off a fellow r3ver. Any other suggestions?

[roguetoaster]

After doing some searching, I can't seem to find anybody who has the exact same symptoms as my car, and all other threads have out of date links and not really any solutions posted.

Since there's such a long list of things it could be, i'm kind of overwhelmed and don't even know where to start. I sprayed starter fluid around my intake and headers to check for leaks, and didn't find anything. Anywhere else I should look for leaks? I bought a new intake boot, AFM, and stock air box to replace the cone filter setup the previous owner installed on the car. Also going to buy an O2 sensor off a fellow r3ver. Any other suggestions?

You seem to have it covered. Report back with your findings.

[DDKing13]

So I took it in to my friend's shop to get it figured out once and for all. Turns out, he said that on 2 of the pistons, the rings are basically non existent, and the pistons themselves need to be redone. He then quoted me about 2 grand to get them repaired.

Something tells me I can buy a brand new set of pistons for less than that. Anybody know where I can find some?

[roguetoaster]

I think he meant cylinders are damaged. Also not sure how he would say the rings are gone without disassembling the engine, bad compression could be found, but not really bad rings.

If your engine is bad I suggest a new one that you get compression and breakdown numbers before you buy. Then redo the timing system on the new engine.

[DDKing13]

I think he meant cylinders are damaged. Also not sure how he would say the rings are gone without disassembling the engine, bad compression could be found, but not really bad rings.

If your engine is bad I suggest a new one that you get compression and breakdown numbers before you buy. Then redo the timing system on the new engine.

not sure, i asked him about the cylinders and he said they were fine.
I'm going to take a look myself when i get some time.

[econti]

Also not sure how he would say the rings are gone without disassembling the engine, bad compression could be found, but not really bad rings.

There is a way. It's not 100% accurate, but pretty close.
You do a compression test, then spray oil into the bore, then do another test.
Compression goes back up to normal, and it's rings, cause the oil seals up the gap enough to stop blowby. Compression doesn't change, and it's probably valves.
Not sure what happens if you blow a head gasket though, I think it wouldn't change.
But yeah. Handy little things to know

[roguetoaster]

There is a way. It's not 100% accurate, but pretty close.
You do a compression test, then spray oil into the bore, then do another test.
Compression goes back up to normal, and it's rings, cause the oil seals up the gap enough to stop blowby. Compression doesn't change, and it's probably valves.
Not sure what happens if you blow a head gasket though, I think it wouldn't change.
But yeah. Handy little things to know

100% correct there, forgot about that.

[oldmann]

Don't give up on the engine yet, This sounds like an ICV, or vacuum leak problem. Pay for a smoke test to find vac. leaks, starter fluid will show you big leaks, but not the small ones.
Unplug the ICV, see if the issue changes, if it does, try cleaning the ICV before buying or trying a replacement.
A friend asking for $2000 to fix this? Thats rebuilt engine money.
Time for a 2nd opinion from another mechanic.

[DDKing13]

update for anybody else facing the dreaded 1222.
Turns out you guys were right, engine was completely fine.
After replacing the injectors, gaskets, accelerator cable, a leaky hose, and cleaning the icv and throttle body, the car ran WAY better, but still didn't get rid of the code. Turned out to be a faulty Fuel Tank Breather Valve. Replaced that, code gone.

BOOM.

[maxmonster]

Sorry to hijack...

I just did my oil filter housing gasket last night. No codes prior to doing the gasket. After changing gasket and driving to work I threw a CEL. This was while I was idling at a light for more than 10 seconds. This also happened before. Stomp test showed 1222 previous CEL also was 1222. Last time I cleaned my ICV and the code went away... Plugs changed probably 2k miles ago along with the valve cover gasket and plug gaskets... Car doesn't idle weird nor do I get variations in my idle...