This is an oddball question that I hope someone may know the answer to. The technicians at the testing facility didn't know the answer. If the technician inputs the incorrect engine info for your pre-OBDII car, can that in itself be the cause of a failure on NOx emissions on a 25/25 test? In perspective, I had my old spare car, a 93 Lumina Euro tested today. The NOx reading on the 25/25 test was 1373/848. (actual/allowed) RPM reading was 2080/3000. Last year when tested, (which was only about 1100 miles ago) the NOx reading on the 25/25 test was 668/848 and RPM reading was 1813/2500. When I noticed the allowed RPM was different this year, I checked all the data on the report. It turns out the technician set up the machine to test a 4 cylinder 2200 engine, although the car has a 6 cylinder 3100 engine. I called them and talked to their lead tech, who knows his stuff as far as I can tell, and asked him if it was possible that the dyno applied incorrect loading because the engine data was entered wrong. He said he didn't know because it had never happened to them before. He will redo the test with the correct engine data entered. The car runs as good as ever right now, and the catalytic converter, egr valve, and spark plugs have all been replaced within the last 3000 miles or so. The oil was just changed, and the engine was warmed up from driving about 45 minutes before the test was done. Anybody know the answer?