91 Si emissions problem...
#1
Member
Thread Starter
Join Date: Jan 2002
Location: Fayetteville, GA, USA
Posts: 1,285
Likes: 0
Received 0 Likes
on
0 Posts
91 Si emissions problem...
I have a 91 Si that I recently purchased. The guy I bought it from gave me a passed emissions form from late last year. The motor had a lot of miles on it, so I swapped the engine from my 90 CRX Si into it. My CRX also passed emissions less than 6 months ago.
I took my Si in today and it failed emissions, all three areas. (HC, CO, and NOx)
This was puzzling to me because while the engine isnt the same, both the car and the engine passed. (Though they werent together at the time)
When I did the swap, is it possible that I may have neglected to hook something up properly that affects the emissions? The car runs perfect and gets 30 mpg.
If it isnt possible I screwed something up, why did it fail? What can I do to fix it?
Thanks
I took my Si in today and it failed emissions, all three areas. (HC, CO, and NOx)
This was puzzling to me because while the engine isnt the same, both the car and the engine passed. (Though they werent together at the time)
When I did the swap, is it possible that I may have neglected to hook something up properly that affects the emissions? The car runs perfect and gets 30 mpg.
If it isnt possible I screwed something up, why did it fail? What can I do to fix it?
Thanks
#4
Member
Thread Starter
Join Date: Jan 2002
Location: Fayetteville, GA, USA
Posts: 1,285
Likes: 0
Received 0 Likes
on
0 Posts
Re: 91 Si emissions problem... (Suck my DX)
I did the swap, and am pretty experienced at it.
My readings are: Allowable
HC-ppm 151 136
CO-% 1.36 .76
NOx ppm 1545 984
That is all at the 25mph test. The 50 is pretty close to the same ratios.
I assume all emissions controls are hooked up, but that is part of my question. Is there a control that would cause it to fail in all three areas?
My readings are: Allowable
HC-ppm 151 136
CO-% 1.36 .76
NOx ppm 1545 984
That is all at the 25mph test. The 50 is pretty close to the same ratios.
I assume all emissions controls are hooked up, but that is part of my question. Is there a control that would cause it to fail in all three areas?
#6
Member
Thread Starter
Join Date: Jan 2002
Location: Fayetteville, GA, USA
Posts: 1,285
Likes: 0
Received 0 Likes
on
0 Posts
Re: 91 Si emissions problem... (charlee)
<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by charlee »</TD></TR><TR><TD CLASS="quote">ur cat would be a must be if u failed emissiond in all 3. thans what im thnking.</TD></TR></TABLE>
Thats what I thought, but the cat worked fine less than a year ago. Could it have gone bad that quickly?
Thats what I thought, but the cat worked fine less than a year ago. Could it have gone bad that quickly?
#7
Honda-Tech Member
Join Date: Dec 2005
Location: San Ramon/Pleasanton, CA, USA
Posts: 1,748
Likes: 0
Received 1 Like
on
1 Post
Re: 91 Si emissions problem... (311)
Three strikes your out, Just kidding.
All three points me to O2 sensor or cat. What is your O2 reading from the test?
How old is the gas in the tank? Have you added any cleaners to the gas?
Usually with a bad cat your Nox numbers would be alot higher, but with all the HC it is hard to tell.
All three points me to O2 sensor or cat. What is your O2 reading from the test?
How old is the gas in the tank? Have you added any cleaners to the gas?
Usually with a bad cat your Nox numbers would be alot higher, but with all the HC it is hard to tell.
Trending Topics
#8
Member
Thread Starter
Join Date: Jan 2002
Location: Fayetteville, GA, USA
Posts: 1,285
Likes: 0
Received 0 Likes
on
0 Posts
Re: 91 Si emissions problem... (thesmogman)
Bringing this back. I replaced my cat, o2 sensor, and changed the oil. I took it back today and passed all of the 25mph tests, but the 15 mph test I failed on
CO-%, and I actually got higher than I did before I replaced everything. My CO-% at 15 mph is 1.46 with an allowable .79.
Any ideas? Everything else passed!?!?!?!
CO-%, and I actually got higher than I did before I replaced everything. My CO-% at 15 mph is 1.46 with an allowable .79.
Any ideas? Everything else passed!?!?!?!
#11
If your vacuum line is disconnected from the Map, your CO will be very high. On the OBD0 vehicles I don't think it will catch it(CEL), unless you have the sensor disconnected.
#14
Member
Thread Starter
Join Date: Jan 2002
Location: Fayetteville, GA, USA
Posts: 1,285
Likes: 0
Received 0 Likes
on
0 Posts
Re: (Mr.Smog)
<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by Mr.Smog »</TD></TR><TR><TD CLASS="quote">Did you warm the car up good? You know the cat has to be broken in once you get it, right. </TD></TR></TABLE>
I didnt know that. The cat has been on for about 300 miles, and I drove the car 50 miles this morning on the way to the testing center.
Is that not enough?
I didnt know that. The cat has been on for about 300 miles, and I drove the car 50 miles this morning on the way to the testing center.
Is that not enough?
#15
Re: (311)
That's more than enough. When a car fails smog at my station then gets the cat replaced, I tell the customer to drive about 5-10 miles. It normanlly works well after that, sorry man I don't kknow what else to say. Even though you replaced the O2, I would double check the connections cause it sounds like you may have a lazy 02. Do you have a chipped ecu? Some of those programs make the fuel curve aggresive. I have a chipped PW0 with my B16a swap in my CRX, CO is around 4-4.5%. I figured I need another ecu cause my mpg is very low and don't wanna pay at the pump. Good luck with your diagnosis, wish I could hepl more.
Thread
Thread Starter
Forum
Replies
Last Post
classciv
Honda CRX / EF Civic (1988 - 1991)
4
04-15-2006 09:06 AM