My 1986 240DL w/225K miles, using no fluids, flunked California Bay Area's new dynamometer Enhanced Test Only smog test, so needs to be junked.
Now, my 1997 850, at 135000 miles, just flunked as well. Nitrous Oxide level over 3,000, as opposed to allowable 400. Volvo dealer by law cannot now offer advise or diagnose. My Smog technician/mechanic, not too familiar with Volvos, re-diagnosed Volvo's recommended air pump, valve, and solenoid repair for $700, as simply a corroded solenoid for $75.00, cleared codes, changed plugs, air cleaner, gave me driving sequence to bring all systems to ready, verified they were all ready, and confidently sent me for test only test, and it flunked, big time. Fuel mixture is too lean, causing excessive NOX. Has since cleaned air injectors, cleaned tops of pistons, checked for vacuum leaks, replaced mass air flow device,
O2 sensor, and generally spent hours trying to diagnose, with very minimal progress in lowering NOX. He's out of ideas; suggested I let Volvo diagnose, since he lacks their computer, who refused, as illegal now that it flunked.
Anyone have a good solution, besides letting another shop charge me $2,000 to replace everything that may or may not be the problem?