Usually the catalyst readiness is achieved before the EVAP readiness. EVAP is ready for 50 miles, but not so the catalyst. I tried to complete all the drive cycles per workshop manual. No codes at all, engine runs great.

Some background: I did the inline thermostat mod and the highest temp I have seen is 190 deg F. Could that be the culprit? Engine does not get hot enough? (I ordered a 195F thermostat and will try that out). Also, I installed a new engine (used P38 4.6) in my '04 D2 and it runs great. No codes from start except the misfire hick-up due to coil relocation, but that has been fixed within the first 10 miles.

 

Finally I passed the smog. I added two bottles of CRC and after driving 30 miles the catalyst became ready, but I don't know if that was really the fix. Before I drove over 280 miles with no effect. The last resort would be replacing the cats for north of $1,200, so I gave the mechanic-in-a-can for $30 a try and it seemed to work.

 

I paid maybe $90 for cats off of Amazon a few years ago and had them installed for maybe $150.

 

I am in California. Cheapest CARB cat is $400 per piece. Shops have hourly rates of $200+. Plus taxes and fees and I am at $1,200.

 

Yikes.