All of a sudden i noticed my car was running really rich so i turned on the scanmaster and the drivers side was at 160 while the passanger side was at 125 ish where it normally is. They use to both be with a few blms of eachother. When i drive the BLM's will go down to 130 but when i get back out of the throttle they go right back up to 160. I did get a code 44 which is lean condition. I am thinking leaking header gasket but i don't really hear one and just looking from the top side i don't see any soot around the gasket. Tonight i will probably pull the header loose and check out the gasket unless anyone else has any ideas of what it could be. The car still runs strong. Thanks

 

sounds very much like an exhaust leak to me probably at the collector, I had the exact same thing, my exhaust leak was so small but at idle the left would just stay at 160 no matter what unless I started driving around, then I left the scanner running & kept tightening the collector bolts on my old slp's & it was so cool to watch the blm's drop on that side

If thats not the case with that cam & aftermarket TB you will see the exact same thing, try backing up the throttle stop screw this way the blades let less air through which forces the IAC valve to open up, the more air you direct through the IAC valve the better the blm's, because the IAC idle discharge ports are right at the ports & for a big cam thats important because of reversion that happens in the intake.

 

The BLM's use to not be split. I think the leak would have to be on the head though because i have SLP shorties and my O2's are in the headers not the y pipe.

 

check for an engine vacuum leak like an unplugged vaccum line on that side or the intake gasket. spray some carb cleaner along the intake gasket and keep an eye on your fuel trims.

 

I'd do a compression check. I had the same symptoms on my 94Z to eventually find the compresion rings bad on two different cylinders. Actually the metal between the rings had let go. 160 means way lean brother, Fred

 

TTT any other ideas. I am going to pull the header tom and inspect the gaskets. I don't think its the rings the car runs real strong and its a new motor. If you got some ideas throw them out for me.

 

Dude I had SLP shorties aswell, o2's are in the headers on mine also, except its weird since my driver's side header was in the Y-pipe & then I got an o2 bung welded onto the header, maybe cuz they are like 3 years old Either way, that donut does not seal very easily, I bet you thats where your problem lays, what happens when your engine is running is its sucking in air through the exhaust aswell as push it out, if there is a leak after the o2's its going to suck in that fresh air & the o2 goes nuts, trust me I had SLP's, & thats what my problem was, don't be lazy just go there & check!

 

I bought my SLP shorties used and they had the the drivers side O2 relocated to the header instead of the ypipe. I just figured a leak after the O2 wouldn't effect it. I figured it had to be before the O2 to cause problems. I will check it out then. Thanks.

 

No problem, & yes it will affect it big time.

 

Well i looked at the collector and it had some soot around it so i pulled the y pipe down and went and got some new gaskets. I fired the car up open header and both sides went to 160 blms so i hope your right bunker and thats my problem. After it cools i will go and put her back together.

 

My left BLM is always 160 at idle and goes to ~128 as soon as I touch the throttle. I had a header gasket leak, but we replaced both sides and it didn't change. I do have Hooker long tubes with the two piece header on the driver's side and it looks like it's not a perfect seal. I wonder if that's my problem.

 

Mine does the same thing. Right side is at 160 when my foot is off the throttle and goes way down as soon as I touch the gas. Probably header leak huh?