Is your NSX failing smog? Read this.
- Thread starter johnnymo
- Start date
Just cleaned mine... and have noticed a HUGE difference in how the car runs.
For such a cheap part... do you think replacing instead of cleaning would make even more of a difference?
I'm shocked in the difference I've noticed thus far...
thank you op!!
For such a cheap part... do you think replacing instead of cleaning would make even more of a difference?
I'm shocked in the difference I've noticed thus far...
thank you op!!
Interesting I actually haven't driven mine since I cleaned the sensor. Maybe I will drive it to work tomorrow.
Good info OP! Thanks for posting
After reading what you guys have posted I decided to clean this sensor as well, since I have failed my smog test in Canada.
My nsx was reading double the limits across the board on a two step idel test. It turns out my senors was caked with oil/ carbon so I cleaned it and it's going back for the emissions test next week. I really hope this fixes my problems.
My nsx currently has 260,000km on it and I have intake, headers, exhaust and the prospeed Rdx injector kit with prospeeds chip.
If it fails again I'm going to have to swap the injectors and ecu back to stock then run it again and hope it passes. Which Im tring to avoid.
Anyways thanks for the info:biggrin:
My nsx was reading double the limits across the board on a two step idel test. It turns out my senors was caked with oil/ carbon so I cleaned it and it's going back for the emissions test next week. I really hope this fixes my problems.
My nsx currently has 260,000km on it and I have intake, headers, exhaust and the prospeed Rdx injector kit with prospeeds chip.
If it fails again I'm going to have to swap the injectors and ecu back to stock then run it again and hope it passes. Which Im tring to avoid.
Anyways thanks for the info:biggrin:
That's interesting because we had a customer with the rdx injector upgrade pass emissions with flying colors here in California. You have a lot of miles on your car... do you still have the factory catalytic converters on them? That could be the culprit.
I do have the stock cats on the car and i think they are still original.
Anyways I went for my smog test again today and my NSX passed.
here are my findings....
This is what the readings when it failed
this is what my Temp Sensor looked like before cleaning.
Here is what the passed test looks like, a huge difference.
Three things changed since my last test,
1. Cleaned the air temp sensor
2. Switched from Shell 91 v-power to Perto-Canada Ultra 94
3. the emission test machine was cleaned( dont know if this would have any bearing on the test)
Looks like the cause of my fail was a really dirty sensor. The gap between the first test and the last test were huge. I didn't know that this temp Sensor made that much of a difference. And I'm glad I don't have to change my injectors and computer back to stock:smile:.
Thanks for the Info and i will be taking out that sensor and cleaning every time i get my emissions done in the future.
I do have the stock cats on the car and i think they are still original.
Anyways I went for my smog test again today and my NSX passed.
here are my findings....
This is what the readings when it failed
this is what my Temp Sensor looked like before cleaning.
Here is what the passed test looks like, a huge difference.
Three things changed since my last test,
1. Cleaned the air temp sensor
2. Switched from Shell 91 v-power to Perto-Canada Ultra 94
3. the emission test machine was cleaned( dont know if this would have any bearing on the test)
Looks like the cause of my fail was a really dirty sensor. The gap between the first test and the last test were huge. I didn't know that this temp Sensor made that much of a difference. And I'm glad I don't have to change my injectors and computer back to stock:smile:.
Thanks for the Info and i will be taking out that sensor and cleaning every time i get my emissions done in the future.
wow...good to know. Might just take mine out and clean it on my 03 just in case as a preventative before I take the car in for emmissions later this year
Yes I believe for any NSX especially older ones this should be part of routine maintenance checks, or at least checked every 2nd season or before the 2yr etest requirement would be good at least in Ontario Canada.
Great info guys.
Just took mine out and it is lightly coated with oil residue and some very small spots that the oil was harden. I used MAF cleaner to be more gentle on the sensor. Car has about 72k miles.
I suppose cleaning it every 30k miles would be OK.
Just took mine out and it is lightly coated with oil residue and some very small spots that the oil was harden. I used MAF cleaner to be more gentle on the sensor. Car has about 72k miles.
I suppose cleaning it every 30k miles would be OK.
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I am in the same boat in So Cal. Pulled mine after I failed today. It was oily but not fouled. New one is on the way.
Another issue in Calif. is we used to be able to test in 1st and 2nd gear. Now its 2nd gear only.
Another bummer, while 91-94's are about the same, 94's have to meet a higher standard? Thats insane IMO.15 MPH HC (PPM) 80 MAX,
NO(PPM) 680 MAX at 15 MPH. I pass at 25 MPH, but not 15 MPH in 2nd gear.
Who makes this stuff up?
There ought to be a law.............
The more I think about it, the madder I am getting. I have a Tall 2nd gear.
How the hell can I test it at 15 mph in 2nd? We should do something as a group.
The car was not designed to run in 2nd gear at 15 MPH!
It looks like they are trying to get these older cars off the road.
And that really burns me up. Any ideas?
Another issue in Calif. is we used to be able to test in 1st and 2nd gear. Now its 2nd gear only.
Another bummer, while 91-94's are about the same, 94's have to meet a higher standard? Thats insane IMO.15 MPH HC (PPM) 80 MAX,
NO(PPM) 680 MAX at 15 MPH. I pass at 25 MPH, but not 15 MPH in 2nd gear.
Who makes this stuff up?
There ought to be a law.............
The more I think about it, the madder I am getting. I have a Tall 2nd gear.
How the hell can I test it at 15 mph in 2nd? We should do something as a group.
The car was not designed to run in 2nd gear at 15 MPH!
It looks like they are trying to get these older cars off the road.
And that really burns me up. Any ideas?
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Thats where I go.....Last few yrs now.
But 2 yrs ago he could test in 1st gear at 15 mph.
Only so much he can do.
This gear change to 2nd at 15 mph is a big deal.
But 2 yrs ago he could test in 1st gear at 15 mph.
Only so much he can do.
This gear change to 2nd at 15 mph is a big deal.
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Orange county has stricter numbers than other county's.
Compared my test from 2 yrs ago and the Max numbers are now lower.
They think these cars improve emissions with age I guess.
Run a test at 15 mph in 2nd gear at 1500 rpm and what do you know?
The car cant do it. I have 64k on my car and it has never run better.
I doubt it could pass this test when brand new.
I plan to check other county numbers & maybe take a drive.
I understand San Diego and Riverside county have better Max, numbers that would help get through this.
Anyone know current numbers for different counties in Calif?
This is just insane.
Compared my test from 2 yrs ago and the Max numbers are now lower.
They think these cars improve emissions with age I guess.
Run a test at 15 mph in 2nd gear at 1500 rpm and what do you know?
The car cant do it. I have 64k on my car and it has never run better.
I doubt it could pass this test when brand new.
I plan to check other county numbers & maybe take a drive.
I understand San Diego and Riverside county have better Max, numbers that would help get through this.
Anyone know current numbers for different counties in Calif?
This is just insane.
I had my last 'Test Only' smog check back in May and although I passed I was right up against the upper limited for HC. When I pulled the sensor it was oily and discolored but had none of the build up as shown in the previous posts. I put a new one easily-screws weren't a problem. I'm up to 80k on my '93 and I've noticed an improvement in both driveability and fuel economy. I'll see if it helped with the HC in 22 months.
I did change my sensor with a new one. Big improvement but needed HC (PPM) 81 or less and got a 91. That was on 7/21/12. On 7/20/12 you needed 80 or less.
You see, these numbers change from day to day.
NO (PPM) MAX is 684 I am at 765. This is 15 mph in 2nd.
I pass no problem at 25 mph in 2nd.
What were your numbers? Just curious.
Thanks
My sensor had a light oil film as well. Lightly tapped the end of the Philips screwdriver with a small hammer as I unscrewed 'em. Came out easily. Super simple task.
You see, these numbers change from day to day.
NO (PPM) MAX is 684 I am at 765. This is 15 mph in 2nd.
I pass no problem at 25 mph in 2nd.
What were your numbers? Just curious.
Thanks
My sensor had a light oil film as well. Lightly tapped the end of the Philips screwdriver with a small hammer as I unscrewed 'em. Came out easily. Super simple task.
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Found out today the EGR valve does not open up until around 2500 rpm.
The engine mgt smog equip is not really even in use at 15 mph in 2nd gear turning 1500 rpm. (Think tall 2nd gear in 91-94's)
I called around and have got nothing but folks telling me they are trying to get these older cars off the road.
Looking for ideas here..........
Am only off by a hair. But not sure where to go from here as it runs perfect.
The engine mgt smog equip is not really even in use at 15 mph in 2nd gear turning 1500 rpm. (Think tall 2nd gear in 91-94's)
I called around and have got nothing but folks telling me they are trying to get these older cars off the road.
Looking for ideas here..........
Am only off by a hair. But not sure where to go from here as it runs perfect.
Order the "clean power" fuel additive. Lots of good info on it lowering the numbers. I'm trying to get some this week since smog is due soon and I don't want to take any chance of failing.
Should I just go ahead and change the temp sensor anyways given the car is almost 10 years old?
I reviewed my results from my May test in NorCal where the 15mph HC max is 86 and the 25mph max is 51 and I was at 85 and 51. For NO at 15mph the max is 697 and at 25mph it's 724. I was at 446 and 274. I run a 4.23 rear gear using a '02 6-speed so my rpms are 1740 at 15mph and 2157 at 25mph. My rear tires are 255/40-17. Perhaps a set of small OD rear tires for smog tests that get the RPM's up even more would help.
The lowered readings are certainly frustrating! I've failed already recently, even after Ramon @ Niguel Motors cleaned this sensor. I also ran Clean Power as suggested and it helped a bit, even after getting new Magnaflow cats installed. The readings all pass except for the NOx at 15mph.
I've replaced:
02 Sensors (2 years ago purchaed from SOS)
New Magnoflow factory replacement cats (took the place of my Random Tech Hi-Flow cats)
Cleaned EGR
Cleaned Throttle Body
Cleaned the sensor in this thread
Less than a year old intake filter
Ran Clean Power and replaced Fuel filter after Clean Power cleaning.
I've just about ran out of ideas and it's frustrating me that it's failing smog. If anyone has any input/suggestions/ideas, please PM me.
I've replaced:
02 Sensors (2 years ago purchaed from SOS)
New Magnoflow factory replacement cats (took the place of my Random Tech Hi-Flow cats)
Cleaned EGR
Cleaned Throttle Body
Cleaned the sensor in this thread
Less than a year old intake filter
Ran Clean Power and replaced Fuel filter after Clean Power cleaning.
I've just about ran out of ideas and it's frustrating me that it's failing smog. If anyone has any input/suggestions/ideas, please PM me.
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