Hi guys I m new to this forum and was wondering if you can help. I have a 1997 mustang gt pretty much stock and it runs very poorly. When I turn it on in the morning it runs rough but no smoke whatsoever and as I start driving it I have to get on it for it to clear up. After that it runs good for a while but sometimes when it idles rpms will drop to about 400-500 and it will shake, smoke and smell like gas. I want to say the smoke has a bluish tint and was thinking valve seals but I m not sure. I just changed the MAF took it for a drive and at first it ran perfect but by the time i got back home i had the same issue. I pinched the IAC hose and it almost stalled. The codes are for upstream and downstream O2s. If it were the valve seals the oil level should decrease right? I changed it about a month ago and was all there. PCV valve is a couple months old. The car stalled while idling twice since I bought it (about 2 years). On a side note there is a red capped hose coming out to the right of the IAC. Does anyone know what the hose is for? I ll try to attach a picture. I dont want to spend a lot on unnecessary parts. Thank you.