The car (1990 740 Turbo, 154,000 mi.) failed the emissions test due to higher than allowed NOx output. CO and HC were fine. Does this vehicle have EGR? I can't find anything that looks like an EGR valve and there are no tubes leading from the exhaust manifold to the intake side. Is the EGR system, if present, part of the turbo?
No, it doesn't have an EGR. Has it had a tuneup recently?
Thanks for the response. I was in the process of doing the tune-up when I thought about the EGR.
Usually, it's the 02 sensor that causes problems, if everything else is in proper shape. You can buy a new one at
MP
MotorsForum website is not affiliated with any of the manufacturers or service providers discussed here. All logos and trade names are the property of their respective owners.