Okay so this is kinda weird me and my fiance both have LS4s and I enjoy my cammed monte carlo ss alot but her Grnad Prix GXP is thrown an engine light for running rich and besides a CAI its compltely stock,and what weird is it comes on and off all the damn time the only thing i can think is the sensors's takin a **** on itself,because ive monitored it and it seems more soich than rich but the damn lights says differently anybody know the answer to this.

 

What's the code? I had to replace my rear O2 sensor a while ago.

 

check all the intake tubing after the maf make sure you arent getting any false air

 

try cleaning and oiling your filter on the CIA

 

problem fixed cleaned the maf and light hant come back and cars stoich again and i found somethin out to the GXP has smaller different maf then the impala ss and my monte carlo ssand the throttle body is exactly one inch smaller to did anybody else know this cause i sure didnt but i gotta say makes me wonder what a monte tb and maf would do on these cars not that she would ever care since she puts it and we take it to get grocceries lol

 

No way. What year is the GXP that had the code 05 by chance

 

As far as I knew the MAF and TB were all the same dimentions for all years. I am almost positive they are. A dirty MAF will make things run rich as well as a bad 0-2 sensor.

-Mike

 

come again?

 

its an 06 gxp my monte is an 07 and yes guys its hard to beleve but there smaller i even checkd the parts at advance were i work the refurbed parts are the same and smaller the buick and the gxp got different mafs and tbs

 

i have a diff cam in my monte carlo is that ur question?

 

^^^ Yup....LS2, LS6???

 

And what kind of cam it is? Pics/Vids?

 

Maybe im an idiot but what the hell is stoich

 

fancy word for air/fuel ratio

 

Ok so I am an idiot. knew it but it didnt click. Carry on

 

Stoich is short for stoichiometric which describes a state where reactants and products are equal and are being consumed/produced in an equal state. Stoich for LSx engines is usually 12.8 to 1 Air-To-Fuel Ration. At that mixture, the reactants are combining at equal rates to produce the most power.

 

LS2 cam pretty common swap not sure why everybody is shocked it not like its a crazy mod and yes stoich is were you ideally want your af at or a little rich never lean

 

Everybody's shocked because LS cams don't fit in our motors off the shelf. Not that common, actually.

 

Not quite.

The theoretically correct stoichiometric AFR, that is, the AFR at which all fuel burns and all oxygen is consumed is 14.7 for gasoline. This is not the AFR where max power or max fuel economy is found, but is the AFR that engines are designed to run at cruise and light acceleration.

12.8 is in the range where "mean best torque" is produced (could be anywhere from 12.4 to 13.1 depending on the engine). Slightly rich mixtures ensure that all oxygen is consumed.

 

Learn something new every day...I had my **** mixed up but I shoot for 12.8 when I tune, I've heard/read in LSx circles that there is where you want to be.

Thanks for helping me out.