I am trying to find easy, cheap ways to bring down NOx levels on a MA emissions test.
My '94 Grand Marquis wasn't driven from Nov. 05- June 06, and then July
06- august 06. Got it inspected basically the day I started it up again in August, and it failed MA emissions for HC (read 1.21- limit 1.20 gpm) and NOx (read ~4.00- limit 2.50). I have driven the car regularly for the past two months, added fuel additive for a couple cycles, and put some oil system additive as well. I had the oil changed, with 15w-40 (heavier than usual), and had the PCV valve replaced as well as fixed a hole in the connector to the valve the day before reinspection (yesterday) and failed NOx again but much lower. It read at 2.87 gpm a limit of 2.5. Passed HC with a reading of 0. 67, so definitely on the right track.I'm trying to keep costs at a minimum, and I'm wondering if the NOx would come down enough just by burning premium fuel or any other quick fixes. I wonder if since its pretty close I could avoid going in replacing things in the EGR system. I just want the car to pass inspection and serve me for another year at the most. Any tips would be greatly appreciated, thanks....