ford lightning running lean on banks 1 and 2!!!!

[frankylightning]

Hello,
Im having issues with my 1999 ford lightning

Hesistation and bogging when "i floor it"

Stock 5.4 sc
Only modd is a #4lb pulley with a diablosport tune
91octane/pulley tune

No check engine light on, but when i plug in my diablo
Trouble codes states its running lean on banks 1 and 2




Please help!!!!!

Thanks........

 

[SVT Phillip]

Check ur plugs

 

[frankylightning]

Im gonna change my plugs.

Which ones should i go with?

Some guy at a local shop said to go with ngk tr6 gap them 35

What do you think??

 

[SmokenGRA03]

Its running lean... You need to get a better tune. The hesitation is probably detonation. Go with NGK TR6 gap at .28-.32.

 

[DSG2003Mach1]

first off has anything changed recently? How long have you had the current pulley/tune on the truck? If youve had it for a while then Id look at mechanical items first. The rubber elbow off the back of the intake is known to rot and cause both banks to go lean. Its not fun to get to but it does happen.

the hesitation/bogging could be from plugs with detonation damage, plugs are old/fouled and/or coil packs as well.

 

[JtothaP]

NGK TR6. Only way to go.

 

[WhiTriCobra]

If you get a bank 1 and bank 2 lean, there is a vac leak before the 02's. nothing with plugs. The main culprit is almost always the rear vac hose at the back/lower of the turkey pan (lower intake). When i had this problem, i could reach my hand back there(won't feel good) and could barely feel it. Thought it felt fine. Tighten exhaust, checked all hoses and so on. Finally decided to take SC and everything off so i could port it, clean the intercooler and finally check that hose a little better. It had a slit in the hose off the port there on the turkey pan. After i ported/cleaned and put a new hose on (some just delete and that's fine) the codes went away and never returned. But if you have a lean bank 1 or 2, it has a vac leak somewhere.