Rebuilt Transmission, Now Fails Smog Check

[RCH]

My daughter has a 1997 SL2 with automatic transmission.
She had to have it rebuilt and the tech told her it might not pass smog check.

She took it to have it smoged and it did fail.

What could potentially cause this?

I don't have the particulars as far as emission levels , she is going to bring the papers by next week so we can try to sort this out.

Breif History:
I rebuilt the engine a couple of years ago and put a new cat on it, it did pass smog after that, then the transmission went out and now will not pass.

Thanks in advance,
Richard

[fdryer]

Since California wants to lead the nation with tail pipe exhaust analyzing as a political move to rid cars quicker than the rest of the nation, you'll have to post the emission numbers. From time to time, members from California with old Saturns ask the same questions because of California's strict emissions that were arbitrarily chosen to be lower than federal EPA standards. In a nutshell, a '97 with OBD II that doesn't display the SES indicator has already passed federal emissions. Mine is the same OBD II but an '03 L300 without tail pipe analyzing in NYS and passes immediately because it meets federal emissions, not California's. Your state wants you to spend more money to lower emissions than federal EPA standards for that model year which already does from the SES indicator not turning on. By lowering emissions for California's standard, you'll have to go line by line on each of the three pollutants (HC, CO, NOx) that doesn't meet state emissions. Hopefully it won't be too costly to keep the car.

[Inkara1]

Definitely need to know the emission levels. There are a bunch of reasons a car can fail smog that have nothing to do with actual emissions, including not yet having completed a wide array of internal tests since the last time the battery was unhooked.

[RCH]

Thanks for responding.
She is supposed to come by in the next couple of days with the test results.

I'll post them then,
but I don't understand why rebuilding the transmission would cause a car to fail that had passed the previous time well under the maximum allowable limits.

Thanks again,
Richard

[fdryer]

Personally, I didn't respond to the xmission causing emissions failure because it doesn't with one exception; if the xmission was poorly rebuilt and loading the engine down incorrectly when (presuming) the car is on rollers during the emissions testing(?). Years ago when I had a wagon with OBD I, NYS required cars to roll onto the gas station equivalent of a car dynamometer to have the car use the transmission under semi-driving conditions to duplicate actual road driving while measuring tail pipe emissions. This 'road test' was standardized back then but is now antiquated when OBD II came out. This basically means every vehicle that has OBD II (around 1996) performs its own emissions self tests every time the engine is started and driven a few miles. As long as the SES/CEL/MIL/engine light stays off during any drive, the car has passed its own emissions tests that meet federal EPA guidelines. Every vehicle since '96 does this. No gas station needed for emissions testing, period. The only reason for states to have inspection stations are to ensure vehicles meet safety requirements (lights, wipers, brakes, etc.) and plug in to state computers to register the vehicle and upload the emission self test result directly from the vehicle to the state computer database, via the DLC - the large "D" shaped connector under the steering wheel.

Does California use rollers during emissions testing or not? These are two large rollers placed close together so the car's drive wheels sit in between them and allow a car to 'drive' as if on the road to allow multiple speeds without the car leaving the shop. A dedicated service bay is used by gas stations unless dedicated facilities are used in California.

[RCH]

Fdryer,
Thanks for your explanation, poorly built transmission causing extra load on the engine makes sense.

I couldn't think of any reason why a transmission rebuild would cause this, but if it is done poorly I could see this.

One thing that struck me as odd is that the guy who rebuilt it told her it may not pass, he must have known he did a crappy job.

When she brings the receipts over I think I will go have a talk with him.

I knew I should have done it myself, but we had just had a falling out so I let her figure it out on her own.
Thanks,
Richard

[rowdydog]

Just going to throw this out there, if they pulled the battery, which the probably did, then the car will have through a drive cycle to retest all the systems, did she go there before this cycle finished? usually takes 50 or60 miles at all types of driving, city and hwy. just saying.

[RCH]

Originally Posted by rowdydog

Just going to throw this out there, if they pulled the battery, which the probably did, then the car will have through a drive cycle to retest all the systems, did she go there before this cycle finished? usually takes 50 or60 miles at all types of driving, city and hwy. just saying.

Yes, it was a little over a year between the rebuild and the smog check.

Is there some way to test this.

I appreciate all the ideas you all are bringing up.
Thanks,
Richard

[Razzle Dazzle]

Could be completely unrelated to transmission. A lot happens in a year. Don't just guess becuase the last thing that was done was the tranny that it means that's the culprit.

Since you say though, that you can rebuild it yourself, I assume that means you know what you're doing though. My first blame would fall on an O2 sensor or the Cat though.

[adventureoflink]

And to expand on Razzle Dazzle's post, I'd also go after the ECTS/connector, especially if it's original. In addition, address the thermostat. the cat I wouldn't worry about unless you get meteorites in it or if it's physically damaged, or if it's set P0420/P0421 at all. How much oil does the car go through? this may be another factor in failing SMOG as well.

You want a brass tipped ECTS, the 188/195 degrees F stant thermostat (or NAPA equivalent), and the connector should be replaced with one from a junked Saturn, specifically the IAT connector, especially if it's damaged or corroded. USE SOLDER AND HEAT SHRINK WRAPS TO TERMINATE THE SPLICES.

but yes, the emissions numbers would help..

[Inkara1]

fdryer, whether a roller is used during smog check or not depends on the county/area. In my county, they use "Smog Check 1," which tests emissions at idle and at 2,500 RPM (but the 2,500 RPM is not under load). In more polluted and more populated areas, they use "Smog Check 2," which tests the car on the roller at 15 and 25 mph (but not at idle, which I think is an important omission considering Smog Check 2 is often done in areas with frequent traffic jams, meaning lots of idling cars). The OP is in San Marcos, and I would be surprised if San Diego County weren't in Smog Check 2.

If it's been a year since the rebuild, it could have nothing to do at all with the transmission. For if it is something with the transmission putting a heavy load on the car, did fuel economy change, or the feeling of how much power the car has?

[fdryer]

^ ^ Thank you for filling in the blanks. My understanding of the older emissions tests are with NYS and the older OBD I standard back then. I asked to know if rollers are used in current California state emissions testing. Its interesting that your state has two categories for different tests. I may not have been clear that I don't associate the recent xmission rebuild with emissions failure. Hopefully, numbers will be put up so we can see where the OP stands.

[RCH]

I just connected my code reader to my daughter's car.
The code that came up was.

P0137
low voltage sensor
bank 1 circuit 2

Would this be an O2 sensor?

[adventureoflink]

Originally Posted by RCH

I just connected my code reader to my daughter's car.
The code that came up was.

P0137
low voltage sensor
bank 1 sensor 2

Would this be an O2 sensor?

@ bold: fixed for you...

That being said, it depends on what you mean by would this be an O2 sensor. Is it an O2 sensor code, yes (related to the one on the cataclytic converter). Is the O2 sensor the main cause of why you're getting this code, probably not.

http://www.obd-codes.com/p0137

[fdryer]

P0137 HO2S-2 CIRCUIT-LOW VOLTAGE

The 2nd (post cat) O2 sensor isn't outputting voltage as if either the sensor is faulty or the catalytic converter isn't heating up. O2 sensors require 600F of heat before they begin to operate. The front O2 sensor varies output in cycles while the rear sensor reads catcon efficiency - high heat output/constant high voltage (0.025v+). As long as the catcon is working at operating temperature then the rear O2 sensor outputs a steady voltage. Either the sensor is faulty or the catcon is.

Your daughter's '97SL2 auto, rebuilt engine w/new catcon

1-Was the coolant sensor ever replaced? Original plastic round nosed one replaced with the flat nosed brass one? The old sensor fails and tends to make the engine run rich all time.

2-Was the old thermostat replaced with a 195F one? The temperature gauge should be between the 1/4 and 1/2 mark. Old coolant sensor/t-stat ran the temperature needle to the 1/4 mark.

The two items above may be causing a rich running condition with the catcon not warming up to operating temperature resulting in the rear O2 sensor not getting up to operating temperature to begin outputting voltage.

An exhaust leak may also cause this condition.

[RCH]

Thanks,
The coolant sensor was replaced with brass unit.
I have replaced the thermostat, but I don't remember the temp range I put in as it's been a few years, but it would have been what was called for on that vehicle.

I( Muffler Shop) did replace the cat. when I rebuilt the engine as it was ruined by the coolant from the blown head gasket.
I will have her monitor the engine temp. to see if it could be that.

The O2 sensors are original, could coolant have caused them to fail as well?

I really do appreciate all of your input.
Thanks,
Richard

[fdryer]

If I'm not mistaken, lead and silicone contaminates O2 sensors and kills them. There are youtube videos on testing them with a propane torch to heat them and measure the <1 vdc output. Between 0.1-0.9 vdc would indicate a good one. Mileage over 150k+ may be another way to determine replacement. If so, its been recommended to use OEM only for best use. I don't think coolant kills catcons.

There are California members here that may help with specifics to get yours past emissions. Hopefully they'll have some input.

[RCH]

Thanks for your help.

I will post solution when resolved.
She will be over in a day or two, I will look at it then.
Richard

[RobertGary1]

Originally Posted by RCH

My daughter has a 1997 SL2 with automatic transmission.
She had to have it rebuilt and the tech told her it might not pass smog check.

BTW: That is not legal in California. The shop should have a state BAR license and they could have an action taken against their license for knowingly repairing a car in such a way that it would not pass (unless he's telling you it needs additional work).

-Robert

[RCH]

I have the numbers, Thanks for helping.

At 15 mph, rpm-1939
CO2=14.4%
O2= .1%
HC=78 ppm (max allowed is 66) This is what failed.
CO=.20%
NO= ppm123

At 25 mph, rpm=2201
CO2=14.5%
O2=.1%
HC=48 ppm (max. allowed is 49)
CO=13%
NO=122 ppm

I did replace the O2 sensor which was causing the P0137 fault code.
(That is what the transmission rebuilder told her would cause the failed test)
P0137 has not returned.
With my code reader I did get a green light on the emissions self test.

Thanks again for the help.
Richard