bored smog tech here - Zilvia.net Forums | Nissan 240SX (Silvia) and Z (Fairlady) Car Forum

techn9ne · 08-06-2008, 05:18 PM

Quote:

Originally Posted by soreballz

My girls car...
91 S13.
95 KA-DE.
New cat.
Timing is perfect.
Recently Seafoamed to clear the carbon deposits.
New plugs, wires, cap and rotor.
EGR works perfectly...

Nox is STILL 6 times over the legal limit. Any ideas?

does she have heinous 3" exhaust? (the car) is the backpressure valve working correctly? is the pulse air hooked up? what test is it failing for?

soreballz · 08-06-2008, 08:56 PM

Quote:

Originally Posted by techn9ne

does she have heinous 3" exhaust? (the car) is the backpressure valve working correctly? is the pulse air hooked up? what test is it failing for?

2.5" exhaust.
Wtf is a "backpressure valve"? Do you mean EGR?
Pulse air is hooked up, not that it would make any difference. The only function of the the pulse air valve is to pre-heat the cat so the car will run "cleaner" before the engine is fully warmed. Since the tests were all done while the car was hot, the PAIR valve wouldn't have made a shit of a difference.

Its failing a regular test-only... 30 mph test, iirc.

Are you sure you're really a smog tech? lol

techn9ne · 08-20-2008, 02:28 PM

Quote:

Originally Posted by soreballz

2.5" exhaust.
Wtf is a "backpressure valve"? Do you mean EGR?
Pulse air is hooked up, not that it would make any difference. The only function of the the pulse air valve is to pre-heat the cat so the car will run "cleaner" before the engine is fully warmed. Since the tests were all done while the car was hot, the PAIR valve wouldn't have made a shit of a difference.

Its failing a regular test-only... 30 mph test, iirc.

Are you sure you're really a smog tech? lol

actually
the purpose of the pair valve is to act as an afterburner during idle and continue the burn of exhaust gasses after they leave the cylinder. the backpressure valve is connected to the exhaust and controls the vacuum going to the egr. if the exhaust is a larger diameter, there wont be enough backpressure going to the valve. since the valve doesnt have sufficient backpressure, it doesnt work correctly, therefore, the egr valve doesnt work correctly.

Carbonsnail · 01-05-2023, 06:22 PM

Are you still answering questions regarding the
CA SMOG test? I have one. Thank you.

01-05-2023, 06:22 PM	#4
Carbonsnail Join Date: Aug 2020 Location: Lancaster CA Age: 61 Posts: 34 Trader Rating: (0) Feedback Score: 0 reviews	Question. Are you still answering questions regarding the CA SMOG test? I have one. Thank you.