Emission Control Help!!!
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Teching In
Joined: Jul 2009
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Emission Control Help!!! Living in California has some drawbacks... One being a PITA of Emissions Control...
I went for the control and I failed with Nox too high at both 15 and 25 MPH. Using information on this forum I diagnosed that the EGR valve had a problem. This was very clear when I used a vacuum pump as the EGR valve didn't move at all while applying vacuum. When I took it out, it was clear that the mechanic that re-installed the engine bumped the EGR valve against the body as the EGR valve was all twisted and the membrane stuck against the body of the EGR.
So, replaced the EGR valve, run a few tests and got back to the Emmisons Control guy.
Now, the Nox is good:
read: 605 ppm max: 689 at 15 mph and read: 511 max: 706 at 25 mph
But I failed on HC. The first time the car was tested with the bad EGR, HC was:
read: 44 max: 58 at 15 mph 1499 RPM and read:21 max: 34 at 25 mph at 2014 rpm
Now, with Nox being fine, I have:
read:58 max: 58 at 15 mph at 1348 rpm and read: 45 max: 34 at 1347 rpm
I used my scan tool and the Oxygen sensors seem to have the right readings and I also validate that the air pump is working as expected. Any suggestion about where to look next?
The car is a 1995 TA with LT1 with a Jasper reman engine that has 7K miles. Any help is very appreciated.
I went for the control and I failed with Nox too high at both 15 and 25 MPH. Using information on this forum I diagnosed that the EGR valve had a problem. This was very clear when I used a vacuum pump as the EGR valve didn't move at all while applying vacuum. When I took it out, it was clear that the mechanic that re-installed the engine bumped the EGR valve against the body as the EGR valve was all twisted and the membrane stuck against the body of the EGR.
So, replaced the EGR valve, run a few tests and got back to the Emmisons Control guy.
Now, the Nox is good:
read: 605 ppm max: 689 at 15 mph and read: 511 max: 706 at 25 mph
But I failed on HC. The first time the car was tested with the bad EGR, HC was:
read: 44 max: 58 at 15 mph 1499 RPM and read:21 max: 34 at 25 mph at 2014 rpm
Now, with Nox being fine, I have:
read:58 max: 58 at 15 mph at 1348 rpm and read: 45 max: 34 at 1347 rpm
I used my scan tool and the Oxygen sensors seem to have the right readings and I also validate that the air pump is working as expected. Any suggestion about where to look next?
The car is a 1995 TA with LT1 with a Jasper reman engine that has 7K miles. Any help is very appreciated.
10 Second Club
Joined: Apr 2002
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From: Cincinnati, Ohio
Incomplete combustion can cause high HC. I'm assuming that the EGR now working is sending exhaust gases back through and raising your HC. Does the car run fine, decent plugs, no codes? Do you have a performance cam? If O.K. try heating the cats up as much as possible before the test (flog the sh@t out of it) and don't turn the car off when you get to the station.
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Teching In
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Thanks 2001WS6Vert. The engine runs just fine... Normal idle, normal power and the exaust tips are "clean"... No dark stuff on them. No special cam. Only a Moroso CAI and a Granatelli MAF for CAI. But I had those last time I went through emmissions and no problem passing. The plugs look fine (very light beige color) and have only around 7K like the reman engine. The only thing I need to fix but I do not think it will produce high HC's is a very small exhaust leak at the junction just after the cat's at the front on the passenger side... All the engine sensors were replaced new when the engine was replaced. The Opti and the plug wires are new also. I also replaced the injectors, fuel pressure regulator and the fuel pump. PCV valve and all the vacum pipes are new. As the car was old, I did a major "refresh" at the time the engine gave up and I had to replace it.
This weekend, I'm going to check for any unmetered air entering the engine but I'm running short of ideas... BTW: I heard about a VRRRM program in California for cars that do not pass the emissions test. According to what the web site say, you can bring your car to a so called "Golden Shield" garage and they will diagnose, fix and pass you and the VRRRM program will pay up to $1200 for the repairs after you pay a $250 deductible... Wonder if there is a catch... Too nice to be true...
This weekend, I'm going to check for any unmetered air entering the engine but I'm running short of ideas... BTW: I heard about a VRRRM program in California for cars that do not pass the emissions test. According to what the web site say, you can bring your car to a so called "Golden Shield" garage and they will diagnose, fix and pass you and the VRRRM program will pay up to $1200 for the repairs after you pay a $250 deductible... Wonder if there is a catch... Too nice to be true...
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Teching In
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Just in case anybody is interested, I went to the Gloden Shield shop, they keept my car 2 days, diagnosed bat catalytic converters, replaced them and passed the smog test. All the values are well below the average now.
Considering that the smog test by itseld costs $50 and $8 additional for the DMV, I paid $200 to have both my catalytic converters replaced... The remaining costs taken care by the VRRRM program... Not bad... Looks like the VRRRM program is planned to last until end 2013.
Considering that the smog test by itseld costs $50 and $8 additional for the DMV, I paid $200 to have both my catalytic converters replaced... The remaining costs taken care by the VRRRM program... Not bad... Looks like the VRRRM program is planned to last until end 2013.
