StreetCreeper
New member
My registration was due late last year. No big deal, just need to smog the ol' girl and be on my way....
Wrong.
Of course, a few days before I am to smog it, the CEL comes on. I pull the codes and they are EVAP codes. Figures...
Sigh.
Ok off to the junkyards I went.
Snagged a nice VSV but decided to just pull the whole EVAP canister in case I needed it too.
Pulled my old EVAP canister and noticed it had a hairline crack. So I went to town on the crack with some RTV instead of switching it with the junkyard one.
Afterwards, the EVAP codes were no more, but still had to wait until the EVAP I/M showed as ready before I could smog.
Of course, before the monitor completed and I could run the smog test, the CEL comes back but this time it's for the transmission solenoids. Specifically the lockup solenoid and one shift solenoid.
(I can't recall how the hot chick got in that pic, but I'm not complaining either...)
I figured I would never pass the smog test with a CEL light on — even if it was just for transmission solenoids.
Sigh... Goddamn smog-nazi mother****ers wanting us all to breath clean air, be healthy & live a long time an shit....
Ok, so I ordered the solenoids and decided to flush the transmission too since it was the original transmission and had about 387,000 miles on it.
I didn't want play detective and figure out which solenoids were the bad ones. So I just elected to replace them all while I was in there.
Once the solenoids were in and I had flushed the transmission, all CEL codes were gone and I sat around and waited until all I/Ms were ready, including the last to show ready — the EVAP monitor.
FINALY the day came. All monitors ready and no codes!
I had also replaced the plugs and wires in anticipation of the smog test so the truck was running like a top. I felt good about the test.
So test day comes around....and I promptly fail. WTF!
Test results showed I was good on everything but the NOx.
California limit for my 97 was 512 ppm max @ 15mph and I tested @ 737ppm. So I was over by 225 parts per million. Goddamn mother****ing son of a b***h c******king bastards...
Breathe...
So I devised a plan for the retest. I pulled the original upstream O2 sensor and put in a new Denso unit. Then pulled the MAF and cleaned it as well. I felt confident that this would do the trick.
Wrong...
Failed the second test too!
F**k s**t p!ss mother****in a**h**e sumbiches!!!! (Not cursing the smog shop but rather the Smog Gods)
Second test shows I was 65 parts per million over the max level of 512 on NOx readings.
Well shit! I think to myself, "I don't want to buy a new CC if I'm that freakin close!"
So I came to the forum and asked for some tricks, tips or old wives tales regarding lowering NOx levels.
I quickly received a few good suggestions that I decided to incorporate into my 3rd and final attempt at passing smog.
I figured I would document as best I could exactly what I had done previously and what the results were — as well as what I was going to do for my 3rd attempt, and the corresponding results....good, bad or otherwise.
I figured if attempt number 3 fails, I would just replace the CC which is the original and clocks in at 19 years old (truck was made in 1996) with nearly 390,000 miles on it.
So attempt number three was preceded by the following:
1)
I bought some CRC Guaranteed To Pass cleaner stuff from Walmart.
Says if you fail the smog test, they will double your money back. Meh...whatever. Figured it couldn't hurt though.
I promptly dumped it in and filled the tank.
I ran a second tank of gas without any additives afterwords. I didn't want any of that shit to be lingering around; plus I wanted to give it time to clear out whatever crap it supposedly removes.
2)
I gave the truck a fresh oil change with Valvoline MaxLife 5-30 synthetic blend. This was different than the Valvoline conventional oil I normally use for my oil changes. I didn't want the old dirty oil emitting any nasty fumes/crap into the exhaust and screwing up my clean truck farts.
3)
I timed my test with when my fuel tank would be empty. So I got up early this morning and headed to the fuel station. My tank was pretty empty and the low fuel light was on. Perfect.
At the fuel station I dumped in 1 quart (32 ounces) of denatured alcohol into the tank, and then promptly pumped in $10 worth of premium fuel. About 4 gallons worth.
4)
I aired up the rear tires (they would be on the dyno rollers during the test) to 45psi. The theory is that the higher pressure will decrease rolling resistance on the dyno and your engine will not have to work as hard. Thereby lowering your emissions.
5)
I then timed my drive to the smog shop so that I would arrive just as they opened and would be first in line. The last two times I went there, my truck sat for about a half hour before they pulled it in.
I wanted the cat hot and ready like a Little Cesar's pizza. So I drove it for about a half hour right up to the smog shop that was to open at 8am.
And they were ****ing closed....
Sat around looking stupid as I contemplated what I wanted to do. I didn't want to wait for another day since I now had alcohol and premium fuel in the tank and I know alcohol shouldn't sit in there for long since it's bad for rubber and stuff.
As I contemplated my next course of action ( basically just furiously Googling all nearby smog shops ) I kept the engine running so the cat stayed hot.
Then as I was pulling out, I notice a guy pull into and start opening up the shop. Sweet!
Once he was set up, he pulled my truck in and proceeded to do his thing.
And the minutes ticked by so ****ing slow...
Finally after what seemed like eternity, the results were in. Pass! But just barely. I was 17 parts per million under the limit.
So despite all the little things I did, the NOx was reduced enough to pass inspection, but not by much. As for what helped the most! I don't know. It worked and that's good enough for me. The Smog Gods must be pleased.
Two years from now when I have to do this again, I'll just plan on buying a new cat if the truck is still running well.
Hopefully this thread will help anyone else out there who is borderline passing. It should be noted however that the HC and CO both went up a bit as the NOx went down.
So if you are borderline in those areas, you may lower your NOx by doing what I did, but inadvertently raise the HC & CO levels enough to fail if they were already close to begin with.
Wrong.
Of course, a few days before I am to smog it, the CEL comes on. I pull the codes and they are EVAP codes. Figures...
Sigh.
Ok off to the junkyards I went.
Snagged a nice VSV but decided to just pull the whole EVAP canister in case I needed it too.
Pulled my old EVAP canister and noticed it had a hairline crack. So I went to town on the crack with some RTV instead of switching it with the junkyard one.
Afterwards, the EVAP codes were no more, but still had to wait until the EVAP I/M showed as ready before I could smog.
Of course, before the monitor completed and I could run the smog test, the CEL comes back but this time it's for the transmission solenoids. Specifically the lockup solenoid and one shift solenoid.
(I can't recall how the hot chick got in that pic, but I'm not complaining either...)
I figured I would never pass the smog test with a CEL light on — even if it was just for transmission solenoids.
Sigh... Goddamn smog-nazi mother****ers wanting us all to breath clean air, be healthy & live a long time an shit....
Ok, so I ordered the solenoids and decided to flush the transmission too since it was the original transmission and had about 387,000 miles on it.
I didn't want play detective and figure out which solenoids were the bad ones. So I just elected to replace them all while I was in there.
Once the solenoids were in and I had flushed the transmission, all CEL codes were gone and I sat around and waited until all I/Ms were ready, including the last to show ready — the EVAP monitor.
FINALY the day came. All monitors ready and no codes!
I had also replaced the plugs and wires in anticipation of the smog test so the truck was running like a top. I felt good about the test.
So test day comes around....and I promptly fail. WTF!
Test results showed I was good on everything but the NOx.
California limit for my 97 was 512 ppm max @ 15mph and I tested @ 737ppm. So I was over by 225 parts per million. Goddamn mother****ing son of a b***h c******king bastards...
Breathe...
So I devised a plan for the retest. I pulled the original upstream O2 sensor and put in a new Denso unit. Then pulled the MAF and cleaned it as well. I felt confident that this would do the trick.
Wrong...
Failed the second test too!
F**k s**t p!ss mother****in a**h**e sumbiches!!!! (Not cursing the smog shop but rather the Smog Gods)
Second test shows I was 65 parts per million over the max level of 512 on NOx readings.
Well shit! I think to myself, "I don't want to buy a new CC if I'm that freakin close!"
So I came to the forum and asked for some tricks, tips or old wives tales regarding lowering NOx levels.
I quickly received a few good suggestions that I decided to incorporate into my 3rd and final attempt at passing smog.
I figured I would document as best I could exactly what I had done previously and what the results were — as well as what I was going to do for my 3rd attempt, and the corresponding results....good, bad or otherwise.
I figured if attempt number 3 fails, I would just replace the CC which is the original and clocks in at 19 years old (truck was made in 1996) with nearly 390,000 miles on it.
So attempt number three was preceded by the following:
1)
I bought some CRC Guaranteed To Pass cleaner stuff from Walmart.
Says if you fail the smog test, they will double your money back. Meh...whatever. Figured it couldn't hurt though.
I promptly dumped it in and filled the tank.
I ran a second tank of gas without any additives afterwords. I didn't want any of that shit to be lingering around; plus I wanted to give it time to clear out whatever crap it supposedly removes.
2)
I gave the truck a fresh oil change with Valvoline MaxLife 5-30 synthetic blend. This was different than the Valvoline conventional oil I normally use for my oil changes. I didn't want the old dirty oil emitting any nasty fumes/crap into the exhaust and screwing up my clean truck farts.
3)
I timed my test with when my fuel tank would be empty. So I got up early this morning and headed to the fuel station. My tank was pretty empty and the low fuel light was on. Perfect.
At the fuel station I dumped in 1 quart (32 ounces) of denatured alcohol into the tank, and then promptly pumped in $10 worth of premium fuel. About 4 gallons worth.
4)
I aired up the rear tires (they would be on the dyno rollers during the test) to 45psi. The theory is that the higher pressure will decrease rolling resistance on the dyno and your engine will not have to work as hard. Thereby lowering your emissions.
5)
I then timed my drive to the smog shop so that I would arrive just as they opened and would be first in line. The last two times I went there, my truck sat for about a half hour before they pulled it in.
I wanted the cat hot and ready like a Little Cesar's pizza. So I drove it for about a half hour right up to the smog shop that was to open at 8am.
And they were ****ing closed....
Sat around looking stupid as I contemplated what I wanted to do. I didn't want to wait for another day since I now had alcohol and premium fuel in the tank and I know alcohol shouldn't sit in there for long since it's bad for rubber and stuff.
As I contemplated my next course of action ( basically just furiously Googling all nearby smog shops ) I kept the engine running so the cat stayed hot.
Then as I was pulling out, I notice a guy pull into and start opening up the shop. Sweet!
Once he was set up, he pulled my truck in and proceeded to do his thing.
And the minutes ticked by so ****ing slow...
Finally after what seemed like eternity, the results were in. Pass! But just barely. I was 17 parts per million under the limit.
So despite all the little things I did, the NOx was reduced enough to pass inspection, but not by much. As for what helped the most! I don't know. It worked and that's good enough for me. The Smog Gods must be pleased.
Two years from now when I have to do this again, I'll just plan on buying a new cat if the truck is still running well.
Hopefully this thread will help anyone else out there who is borderline passing. It should be noted however that the HC and CO both went up a bit as the NOx went down.
So if you are borderline in those areas, you may lower your NOx by doing what I did, but inadvertently raise the HC & CO levels enough to fail if they were already close to begin with.
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