High NO on CA Smog
Thread Starter
Intermediate
Joined: Jul 2019
Posts: 30
Likes: 1
High NO on CA Smog
1995 LT1 base. Car had 50,000 original miles on it. Aftermarket BBK TB, JET Performance chip, CAT back exhaust.l, K&N filter with the top of the filter compartment cut off. All CARB Compliant stuff with stickers.
NO at idle and load were both about 200 over on NOX emissions. The mechanic had a heck of a time getting the sensor stick both in and out of the muffler..
First question: if that sensor stick is shoved too deep in the exhaust, will it read high NO.
Second question: any way to lower the reading without pulling the intake and cleaning out the NO Exhaust port?
Any and all advice (other than move out of CA), tips, or TRICKS are GREATLY appreciated!!
NO at idle and load were both about 200 over on NOX emissions. The mechanic had a heck of a time getting the sensor stick both in and out of the muffler..
First question: if that sensor stick is shoved too deep in the exhaust, will it read high NO.
Second question: any way to lower the reading without pulling the intake and cleaning out the NO Exhaust port?
Any and all advice (other than move out of CA), tips, or TRICKS are GREATLY appreciated!!
Drifting
Joined: Apr 2020
Posts: 1,925
Likes: 610
From: Orange, CA
Curious what a "JET performance chip" is on a '95.
To answer your first question, no. There's no way for the tech to stick the sniffer so far into the exhaust that it'll read wrong. The catalytic converters are all the way up next to the oil pan. There's more than enough distance for the catalyzed exhaust gases to travel.
Best of luck with the smog. Hopefully some folks can help you our with your NOx.
To answer your first question, no. There's no way for the tech to stick the sniffer so far into the exhaust that it'll read wrong. The catalytic converters are all the way up next to the oil pan. There's more than enough distance for the catalyzed exhaust gases to travel.
Best of luck with the smog. Hopefully some folks can help you our with your NOx.
Melting Slicks
Joined: Jun 2011
Posts: 2,383
Likes: 385
From: Leland , North Carolina
1995 LT1 base. Car had 50,000 original miles on it. Aftermarket BBK TB, JET Performance chip, CAT back exhaust.l, K&N filter with the top of the filter compartment cut off. All CARB Compliant stuff with stickers.
NO at idle and load were both about 200 over on NOX emissions. The mechanic had a heck of a time getting the sensor stick both in and out of the muffler..
First question: if that sensor stick is shoved too deep in the exhaust, will it read high NO.
Second question: any way to lower the reading without pulling the intake and cleaning out the NO Exhaust port?
Any and all advice (other than move out of CA), tips, or TRICKS are GREATLY appreciated!!
NO at idle and load were both about 200 over on NOX emissions. The mechanic had a heck of a time getting the sensor stick both in and out of the muffler..
First question: if that sensor stick is shoved too deep in the exhaust, will it read high NO.
Second question: any way to lower the reading without pulling the intake and cleaning out the NO Exhaust port?
Any and all advice (other than move out of CA), tips, or TRICKS are GREATLY appreciated!!
Drifting
Joined: Apr 2020
Posts: 1,925
Likes: 610
From: Orange, CA
That's very strange. The '95 PCM uses a flash chip that can be reprogrammed from the ALDL connector under the dash (like modern cars), so I'm not sure what a piggyback would do. In addition the plug on that 'chip/module' don't match anything on the PCM.
Might not be relevant to your issues, but it is curious. I wonder what would happen if you just removed it.
Might not be relevant to your issues, but it is curious. I wonder what would happen if you just removed it.
