PI heads,intake:lean side1 and 2

grampastoy · 06-30-2008, 12:14 AM

recently installed PI heads and intake from FRPP on my 97 4.6 Romeo engine. Now I get a lean burn side 1 and 2. have reset and check engine light reappears after 20-30 miles. car also has new 2.5 inch exhaust to flowmaster delta 50s. also K&N air filter element. cleaned MAF with tuner/cleaner. Bilstien shocks shouldn't matter. Car runs well. What do I change to eliminate check engine? 24lb injectors?

blackstallion666 · 06-30-2008, 12:57 AM

first things first check for any vacuum leaks.

livefast1 · 06-30-2008, 01:01 AM

check for vacuum leaks, check for exhaust leaks, did you get a tune for the pi heads? i would think installing better flowing heads would call for fuel trim adjustments as your providing the engine with more air, causing your lean condition.

grampastoy · 06-30-2008, 09:36 AM

Thanks for the help. Tell me more about the "tune" for the pi. Doubt this has been done. Thanks.

livefast1 · 06-30-2008, 12:18 PM

with your upgrades all being installed at the same time your increasing the amount of air available to the cylinders, thus calling for more fuel. this could bring on a lean code as the 02 sensors will notice the increase in oxygen present in the exhaust. if everything checks out mechanically sound then you more than likely need a tune, a mail order tune using a programmer would do for your upgrades, a dyno tune would be better but will cost more.

grampastoy · 06-30-2008, 07:36 PM

Thanks for your input. Are their any specific programmers recommended? Or good used?
I did find a few hoses that were not entirely in place. One moved on 3/16 inch and the other 7/16. They are directly behind the paasenger cylinder head and down 5-6 inches. Made some large chopsticks to get a hold on them.

Also reset the check engine. Will see how it goes.

ddmsgtr1 · 06-30-2008, 08:16 PM

For our cars, SCT software is pretty widely used. You can get a mailorder tune from almost anybody who carries SCT nowadays, but most people have been recommending Brenspeed, but like livefast1 said, a dyno tune would be nice.