Sounds like I need to get rid of the warm air hose (or plug it) and get a low-temp thermostat (or no thermostat). Thanks for the extra info--especially about Pulseair. Wasn't aware of its function at all.

Also forgot to answer your question -- in CA the NOx is measured at 15mph and 25mph. Both are at about 1700 rpm. It was very high on both (something like 3,000 ppm when it should be in the 200-300 range). I've considered pulling the thermostat as the temperature gauge reading too low doesn't automat...

First -- I don't plan on making the car's computer EGR-compliant, just adding a mechanical EGR. Looks like non-CA, non-ECU controlled EGR used a wax thermostat through which the vacuum was inhibited until 140 degree coolant temperature. If possible I'll simply add that into the system, along with a ...

Lacking any replies over the weekend I went junkyard-diving. I ended up finding a 940 NA from which I extracted the exhaust manifold and intake manifold as well as the hard lines between the two and the EGR. I wasn't certain about the EGR because it has a sensor on it that apparently fed back into t...

I purchased a 1988 740 from Florida that was originally without EGR. I live in California. Unfortunately all my smog readings were off the charts bad, with a number of remedies recommended and executed including a new CA cat, cleaning the TB, new oxygen sensor, replacing a few very old vacuum lines....