Originally Posted by genewants to know
Went in today for Calif. Emissions test on my Ram 1500, 5.2l 318 4x4.
The test failed on Nox at 15mph it passed on 25mph. I recently repaced the furel pump and fuel filter. 188,000 miles still runs strong. Any ideas on what I may try to do in order to pass this state test for registration renewal.
At 15mph @1451 rpm measured 1265 NO (PPM) MAX Allowable is 999.
Thanks for any assistance
You don't have a carburetor on this engine. It's MPI, multi point fuel injection, which is another way of saying EFI. So, you can't adjust it as the PCM (computer) controls it.
What is your tire size?
Go do a tune up. This means replace spark plugs, wires, distributor cap, and rotor. DO NOT TRY TO TURN THE Distributor thinking it will change timing. It does not!! Get everything from Napa as these engines in stock form don't need anything fancy. I would do SEAFOAM before the Tune Up. I'd also do a oil/filter change after the tune up.
Another low cost thing to change out is the PCV valve. It is located on the valve cover. ONLY buy this part from the dealer. Specs on the dealer part are different from ones at the general auto parts store. This is like $10 part. Get new valve cover grommets too just in case the old ones are trash.