Failing emission test

[Smpol19]

My car is an 89 Wagon, F.I. EA-82 145,000 miles failed emission test on high NOx in VA, limit is a little under 1000 and my car had around 1500 at 15 and 25 mph. I'm thinking its probably the Cat but i'm really not sure I can spend that much money on this car as its not my daily driver. I've heard the EGR can have something to do with the NOx but i'm not sure how to check this, the lines are all clear and when I move the throtle I can feel the EGR valve moving. On most other cars I've worked on when I push the EGR valve in all the way at idle the car will stall, this isn't happing, would this indicate a leaking valve? Thinking i'll probably try on a junkyard one tomorrow if I can find one but any ideas would be much appriciated.

[NorthWet]

For NOx, the EGR and the (first?) catalytic converter are the main controls. A leaky valve would allow EGR all of the time, so your stall test probably does not indicate a leaky valve. You might have blockage somewheres, however.

 

I would think (without any specific information to back it up at the moment) that 15 to 25 MPH would not be getting into the midrange where the EGR would be operating. Could be wrong...

 

Was the car properly warmed immediately before the test? If the catcons are not up to normal working temp they wil not function well.

[northguy]

Do a search on emissions tests. Edrach wrote up an almost foolproof remedy/recipe. It is the cat's meow.

[naru]

My car is an 89 Wagon, F.I. EA-82 145,000 miles failed emission test on high NOx in VA, limit is a little under 1000 and my car had around 1500 at 15 and 25 mph. I'm thinking its probably the Cat but i'm really not sure I can spend that much money on this car as its not my daily driver. I've heard the EGR can have something to do with the NOx but i'm not sure how to check this, the lines are all clear and when I move the throtle I can feel the EGR valve moving. On most other cars I've worked on when I push the EGR valve in all the way at idle the car will stall, this isn't happing, would this indicate a leaking valve? Thinking i'll probably try on a junkyard one tomorrow if I can find one but any ideas would be much appriciated.

 

If rpm doesn`t decrease when the valve is opened by hand at idle,most likely the port is blocked.

[Smpol19]

Yes the car was warmed up, I drove it around a bit and then let it idle when i was in line behind 2 cars. I had some trouble finding the write but by Edrach, though i did find some stuff about adding Heet to 1/4 tank of gas, looked intersting. The RPM did drop when I moved the EGR valve just didn't stall. I probably should do plugs, wires and an oil change anyway, but I've heard those really only effect the Hydro Carbons and the CO.

Thanks!

[torxxx]

dump in 6 bottles of yellow HEET with a 1/4 tank of gas

 

and drive it hard before the test. get that cat nice and hot.

it'll pass

[Smpol19]

Alright well thanks for all the help guys, i ran some seafoam through it, cleaned out some vacume lines, and then did the thing with the HEET. This time the NOx droped way down to 760 from over 1500, the limit is around 1000. But now the HC and the CO are both way over the limit, during the first test these weren't anywhere near the limit. Was this caused by the HEET(the yellow bottle) or is it somehting else, I only drove about 200 miles between tests.

 

Results:

limit 15mph/25mph Test 1 15mph/25mph Test 2 15mph/25mph

HC ppm 159/154 34/135 197/189

 

CO% .90/.95 .01/.01 2.17/1.91

 

NO PPM 1097/999 1634/1552 760/765

 

Bold=fail

 

 

Thanks for the help

 

 

Edit: i can't get the results to come up the way I want so they are readable, i'll scan in the results later on....

[Cougar]

If the plug wires haven't been changed in a long time then changing them along with the plugs would be good. Perhaps the cap and rotor also. I would recommend you use NGK plugs. I would also fill up the tank using your normal gasoline to help purge out any of the Heet that may be left.