- Thread starter
- #21
AV8R
Well-known member
Update
So far the following have been replaced:
- EGR negative pressure
- Solenoid
- 3 MagnaFlow cats
The following were tested as good;
- vacuum lines
- ECM pulse modulation
- solenoid turns on at correct times with car on dynamo
- sufficient engine vacuum
and still the SMOG test fail with hi NOx... until a rag is put into the tail pipe, which gives the EGR enough back pressure to open up as expected.
When the EGR works, the NOx is low as it should be (which means the Cats are doing their job).
What is now suspect are the mufflers or perhaps the Cats aren't restrictive enough to allow the EGR valve to work properly.
Does anyone know if the MagnaFlow cats I referenced are correct replacements for the OEM ones?
Regarding mufflers:
- what is the correct part numbers or where can I find OEM ones?
- how do you know if a muffler isn't generating the proper restriction for the 90 vette's system for CA specs?
So far the following have been replaced:
- EGR negative pressure
- Solenoid
- 3 MagnaFlow cats
The following were tested as good;
- vacuum lines
- ECM pulse modulation
- solenoid turns on at correct times with car on dynamo
- sufficient engine vacuum
and still the SMOG test fail with hi NOx... until a rag is put into the tail pipe, which gives the EGR enough back pressure to open up as expected.
When the EGR works, the NOx is low as it should be (which means the Cats are doing their job).
What is now suspect are the mufflers or perhaps the Cats aren't restrictive enough to allow the EGR valve to work properly.
Does anyone know if the MagnaFlow cats I referenced are correct replacements for the OEM ones?
Regarding mufflers:
- what is the correct part numbers or where can I find OEM ones?
- how do you know if a muffler isn't generating the proper restriction for the 90 vette's system for CA specs?