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90scmxdream
04-04-2012, 06:05 PM
Hi I took the sc today for the smog chek and it fail emission ,he said the cats are not good, and he gave me a prize. for cats $620, labor $180. is not that to expensive ?? do you know if there is something less expensive ? please help
jose.:

Ddubb
04-04-2012, 06:48 PM
What are the numbers ? What did you fail on ? NOX too high ? HC's ??


- Dan

90scmxdream
04-04-2012, 07:40 PM
Dan it fail nox the numbers are max 530 meas 945.

Ddubb
04-04-2012, 07:57 PM
I dont think new Cats will fix your problem either. Maybe they will lower the numbers down a little but not a whole lot.

Nox = Nitrogen and Oxygen combined at high temperatures, too much Oxygen in your system.

NOX too high is from too high of temperatures in the combusion chamber - or your engine is running too hot alltogether.


Usually the EGR lowers the temp by adding extra air ( burned air has less oxygen in it, the hot air displaces the oxygen in your engine ) but your car does not have EGR.

Timing could affect this, but timing is non-adjustable on these engines also.

You could also have a vacuum leak making the engine run too lean. I would check for vacuum leaks first, then make sure your o2 sensor, MAF sensor are working good, and Check your Fuel pressure also, too low of fuel pressure will make it run lean also.


- Dan

91BLOWNBIRD
04-05-2012, 03:38 PM
I dont think new Cats will fix your problem either. Maybe they will lower the numbers down a little but not a whole lot.

Nox = Nitrogen and Oxygen combined at high temperatures, too much Oxygen in your system.

NOX too high is from too high of temperatures in the combusion chamber - or your engine is running too hot alltogether.


Usually the EGR lowers the temp by adding extra air ( burned air has less oxygen in it, the hot air displaces the oxygen in your engine ) but your car does not have EGR.

Timing could affect this, but timing is non-adjustable on these engines also.

You could also have a vacuum leak making the engine run too lean. I would check for vacuum leaks first, then make sure your o2 sensor, MAF sensor are working good, and Check your Fuel pressure also, too low of fuel pressure will make it run lean also.


- Dan

I will 2nd and 3rd Dan's comment...check for vac leaks, if all good then make sure you aren't running lean, then if all good replace CATS...

and yes that is far too much $ for CA legal CATS to be installed...I would say $400 out the door $150ea CAT and $100 labor

90scmxdream
04-05-2012, 05:41 PM
hmmmm .Dan remember i have I manual switch to turn the fan on well yesterday when I took the car to smog I forget to turn it on and by the time ,
I did the car was already to hot
the technician told me the car fail mainly because the car was running hot.
jose