Ok i installed my thorley headers and took my cats off so i bought some 02 simms but they wont plug in? Could some1 point out sumin i might be doin wrong or missin? thanks!

 

I think there are two different types of O2s connections that GM uses. One plug pattern is different from the other. I believe one is a square fitting while on the other, the pins are just in a straight row.

 

If the O2 simms are for the cars, then you will either need to send them back for ones that fit the trucks, or cut the connectors off and splice the wires together and toss out the non-matching connectors.

I had to splice my wires in. I think the simm had a female connector, and so did my wire harness. Mine were square.

 

I bought mine from Thunder Racing plugged in and worked perfectly send the wrong ones back and give them a call.

 

Did u but the ones with the black or gray connector thats whats confusing me? And what year is ure truck? BTW i have LT headers so i have to buy extensions but Thunder racing dont sell extensions?

 

I have ASM longtube headers and the Thunder Racing sims matched the plug.Just plug the sims into the harness and zip tie them out of the way.It should'nt make any difference what kind headers you have as long as the plug on the sims matches the O2 sensor plug.My truck is an 01 model.

 

THANKS whitt! But did u buy the black or gray connector if u remember? And when u plug the simulator into the 02 sensor. What about the plug-in the 02 sensor plugs into when u dont have a sim on and when its stock? Do u just plug the simm into the 02 sensor and leave the other plug- in sittin there empty? thanks!

 

I don't have cats,the sims stay plugged into the harness and are zip tied out of the way.I don't really remember how the plug was configured.When I ordered my sims I just told the guys at Thunder Racing that the sims were for a 01 5.3 Tahoe and they sent the correct sim.

 

This may sound silly but... you are attempting to plug the Simms into the REAR O2 plugs right?

I think that 99-00 have different plugs than the 01+