Smog Check Failed? NO too high... suggestions?

[1stGenSHO]

GEN1SHO,

I just failed my smog check in Arizona for the same exact thing in my '90 SHO. Although mine is bone stock, the cause is the cats. After 12 years of abuse they have given up. If you don't want to replace the whole Y-pipe you should be able to have new cats welded in for much less $.
Good Luck.

1stGenSHO

 

[twr]

Put the stock MAF back in and pull the LPM. If the car doesn't pass something else is going on. The Fuel Pump or Fuel Pressure Regulator maybe getting weak.

I would recheck the TPS voltage, constant power should be 5 volts + or - a tenth. If your only getting .1 volts - the car shouldn't be running. If indeed the voltage is low, check it at the BAP, ACT and the MAF, they share the same circuit (as I recall)

I recently failed Colorado emissions (rich) Turned out to be the MAF was dirty, cost me $75 to find that out

 

[GreenBird]

SHO Boom:
87 octane burns at a lower temp? i dont think thats true, it is more explosive than 91, but i dont think it burns colder, even if it did, how does that help?

It's not more expolsive. 93 burns at a higher temp, hence the higher the octane rating, the greater it's resistence to detonation.

 

[greg geraci]

On mine it was my egr valve wasn't comming on which created heavy emmissions.The way I trouble shot it was simmulated vacuume to the egr valve which dropped my emmissions. I replaced my vacuume moduale next to the egr valve that the line goes to off the egr and it passed . Can't say thats the problem with yours but it was for mine. It's a start anyways. Some times if you take off the egr valve you'll find that it gets plugged up with crud. I cleaned it out and that helped also.Bottom line mine was the egr circuit

G
Good luck

 

[jedhead]

Thread is three years old. I am sure its been taken care of.

Bob

 

[greg geraci]

You know what? I just noticed that about being an old threadI'm starting to get the hang of things.
Greg