I was tuned by IVEY about a year ago with just basic bolt ons. A/F's were good now all of a sudden its leaning out to mid to high 12's at mid to high rpm range under full throttle. i have checked my fpr(stock), cleaned my MAF and MAP, changed my spark plugs. i have no codes any suggestions????? NEED HELP! anybody ave this problem before?

 

No hoses popped off the FPR? That's all I can suggest...or believe it might be.

 

No everything is attached. Now what's happening is it is leaning out normal driving I can't give it any more than a quarter throttle without it really leaning out like 17-18 bad bad bad I am goning to put my buddies fuel pump in and see what happens.

 

in the case that it is that lean I wouldnt drive it too much until you address the problem because obviously it could cause a problem if bad enough.

 

long shot, but maybe a case of bad fuel? I had a bad E85 mixture once, where the station mixed up diesel in the tank. I was getting 17-18 afr, and the car knocks even with blibbing the throttle. Just a thought.

 

Bad fuel or fuel pump is failing. I'm experiencing the same thing. More flow is required to keep it richer at that rpm level, my first guess after the fpr hose is the fuel pump. I don't know that I've ever heard of a stock fpr failing.

 

Is your WB reading right? O2 sensor needs replacing. If the condition are true, then Fuel Pump and is a cheap place to start.

 

What's really weird is I drove normal let my tank run out refueled and it ran ok again so I thought it was bad gas and it was fixed. Then like an hour later just cruising normal going up a little hill under the slightest load it sounded funny so I glanced at my Gaige and the a/fs jumped to 17 quick so gave it some gas again an went right to lean. I thought it was my sensor but it is giving me all the symptoms of actually being lean sounds terrible I think my car is dying. Gonna hook a fuel pressure gauge to it and replace the pump tomorrow fingers are crossed

 

I think I found the problem the rubber grommet that is on the fuel pump that acts as an o ring is destroyed all torn up so I was losing fuel pressure new one is ordered this SHOULD cure everything.