My '01 LS1 has a phenomenon where every couple of months, my motor starts to missfire. It only happen occasionally, but when it does it's bad. It happens when I cruise, but if I step on the accelerator, it goes like normal. Once I cruise again, it starts to miss again. The engine light comes on and gives me "Bank 1 too lean". Some have said the MAF sensor is dirty since I have the FIPK kit on it, but it's clean. No real mods to the car, just Headers, Borla exhaust, throttle body spacer and the FIPK system. Any Thoughts or solutions??

 

vacuum leak intake gaskets, 02 sensors on the driver side, failing fuel injectors.

 

Also could be intermittent MAF snsr. The key to diagnosis would be to have a scanner on it at/while the vehicle is acting up, then you could see MAF gms/per sec and mhz if its a MAF issue, or O2 snsrs, etc... Doesnt sound like ignition since its under a light load but when was the last time you changed plugs and what is the gap on them?

 

i was gonna ask if it had a cam then tell u thats normal BUT... i would check the o2 had this happen to me alot..

 

fuel pump, any chk engine lights?

 

check your grounds on back of heads.bad grounds cause freaky ****

 

check the o2's as mentioned above sometimes if they get wet and wires are exposed theyll short out

 

grounds
same thing happened to my brotherinlaws it was a overlooked ground took him a year to find it