Is is hard to retard the timing on a 91 v-6.I would like to do this to help me get thru emmissions as last time I was a little too high in the HC area.Or is there any other way that I can precondition the cat convertor to help it get thru?Plugs,wires,dist. cap are good and oil is freash.Ever since I got a new cat put on at USA muffler I've had trouble passing.I guess thats the differance between a Toyota part and a universal one from a muffler shop.

 

OBDC II computer on that one, Im pretty sure so you would need to reprogram. Im thinking you might need to run 91 octane for inspection or octane booster, but I would run injector cleaner first. make sure you have the car good and warmed up also. I have had same trouble with a OEM converter on a 94 SE.

 

91 octane might serve as a bandaid fix for high NOx emissions, but likely not for hi HC's. If you are certain your ignition components are still fresh and your timing is spot on- i would suggest you check your 02 sensor for proper operation. It should cycle from lean to rich several times per second when the engine held at a steady open throttle (2500rpm).


JJ

 

well u could put it on a computer controlled engine with a knock sensor but , the knock sensor will pick up the vibrations from the gear drive and retard ignition timing, this is why they tell u not to use it on a computer controlled engine