High CO and HC values. Need help! - ZR-1 Net Registry Forums

ajaxajax2000 · 06-20-2007

At the car inspection today I got remarks on high CO and HC values at idle.

Engine also runs a little un-even when driving. No warning lights up. Any ideas as to possible cause and relevant cure?

It's a '92 with 53K on the meter.

TIA

Peter

John Boothby · 06-20-2007

Was your Full Power switch on? This should not make any difference. However, I had my 1990 smogged and it showed high HC with the switch on and when I turned it to Normal it passed. Go figure!

ajaxajax2000 · 06-20-2007

Quote:

Originally Posted by John Boothby

Was your Full Power switch on? This should not make any difference. However, I had my 1990 smogged and it showed high HC with the switch on and when I turned it to Normal it passed. Go figure!

Nope, didn't even have the key in. And I'm not getting any diagnostic codes. It just keeps pumping out code 12 continousely.

tccrab · 06-20-2007

High CO and HC's would tend to indicate that you're running rich.
What condition are your plugs?
It could be many things, from something as simple as fouled plugs, a bad or going bad sensor, leaky injectors, or just bad cats.

Good luck!!

tomtom72 · 06-21-2007

I'm gonna say something but it's directed at the inspectors and not you Pete.....those guys made sure that the car was in "closed loop" before they sniffed her?

Okay, if it was in closed loop, then I say scan it & look at the cross counts on the O2's. Or don't scan & check the plugs, coils & wires and if ya come up empty then scan the O2's. Does it smell rich @ idle? Then look at the Integrator #'s & block learn #'s....maybe a coupla of leakers? Very badrotten egg smell, could be cats going south? Oh, the air filter is good??

Tom

06-20-2007	#1
ajaxajax2000 Join Date: Aug 2006 Location: Sweden Posts: 95	High CO and HC values. Need help! At the car inspection today I got remarks on high CO and HC values at idle. Engine also runs a little un-even when driving. No warning lights up. Any ideas as to possible cause and relevant cure? It's a '92 with 53K on the meter. TIA Peter __________________ '92 ZR-1, black on black, mostly stock (sold)

06-20-2007	#2
John Boothby Join Date: Jul 2005 Location: Las Vegas, Nevada Posts: 777	Re: High CO and HC values. Need help! Was your Full Power switch on? This should not make any difference. However, I had my 1990 smogged and it showed high HC with the switch on and when I turned it to Normal it passed. Go figure! __________________ JB 1990 #148 Red/Saddle Haibeck AYBKG5 Chip/RC Engineering/Flowmasters/K&N/Samco/Fuzzy Dice :cheers:

06-20-2007	#4
tccrab Join Date: Oct 2004 Location: Folsom CA Posts: 1,650	Re: High CO and HC values. Need help! High CO and HC's would tend to indicate that you're running rich. What condition are your plugs? It could be many things, from something as simple as fouled plugs, a bad or going bad sensor, leaky injectors, or just bad cats. Good luck!! __________________ TomC '90ZR1 #792 Honorary Pirate [B]If it ain't FUN, you're doing something terribly WRONG. [/B]

06-21-2007	#5
tomtom72 Join Date: Dec 2004 Location: Jacksonville, FL USA Posts: 4,645	Re: High CO and HC values. Need help! I'm gonna say something but it's directed at the inspectors and not you Pete.....those guys made sure that the car was in "closed loop" before they sniffed her? Okay, if it was in closed loop, then I say scan it & look at the cross counts on the O2's. Or don't scan & check the plugs, coils & wires and if ya come up empty then scan the O2's. Does it smell rich @ idle? Then look at the Integrator #'s & block learn #'s....maybe a coupla of leakers? Very badrotten egg smell, could be cats going south? Oh, the air filter is good?? Tom __________________ 1990 ZR-1, Black/grey, #2233, stock. ZR-1 Net Reg Founding Member #316 & NCM member