Hey Folks, My 1989 240 wagon failed the California smog test twice now, and I can't figure it out. I'm on the verge of taking it to a mechanic, but I'd like to see if anything jumps out at anybody.

I took it in once, and it failed, but just barely. I gave it new plugs, wires, a cap and rotor, a new crankshaft position sensor, a new (used) ECU, a new fuel trap kit, cleaned the oil trap AND the throttle body, and the numbers are WAY WORSE!

The car, incidentally is a 49-state car, and no EGR (pretty sure).

Late last month, my car failed the EVAP test, but I found and replaced a broken rubber hose leading to the rollover valve. My re-test a couple of days ago showed that it now passes EVAP. That's the good news.

The bad news is that my NO (PPM) numbers are way higher now. Last month, my NO (PPM) was:

NO(PPM)
15 mph - MAX:791 MEAS:0877 FAIL
25 mph - MAX:730 MEAS:0497 PASS

After the tune-up and replacement of the ECU and crankshaft position sensor, AND after driving at least 40-50 miles in all conditions (uphill, freeway, in-town) to let the ECU re-learn and warming the car up on the freeway, my retest showed:

NO(PPM)
15 mph - MAX:791 MEAS:1953 FAIL
25 mph - MAX:730 MEAS:1295 FAIL

SO, I barely failed before, but after a tune-up, new ECU, new crankshaft position sensor, new flame trap, clean oil trap and clean throttle body, the numbers are off the charts. (I did a bonehead thing and accidentally switched two plug wires at some point during my repairs and drove/limped the car around the block before discovering my mistake - does anyone think I could have ruined something because of this?) I've checked the internet and can't seem to find anything that applies to my situation.

I just went out and sprayed starting fluid around the throttle body and the the intake hoses with the motor running, and the engine didn't rev higher at all.

What's weird is the car runs great now. So much smoother and quieter than before. And my temperature gauge indicates cooler running temperatures than before.

My HC and CO didn't change significantly between tests. Here are the "before" numbers:

HC (PPM):
15 mph - MAX:116 MEAS:94 PASS
25 mph - MAX:91 MEAS:58 PASS

CO(%):
15 mph - MAX:.74 MEAS:.27 PASS
25 mph - MAX:.62 MEAS:.14 PASS

and the after numbers:

HC (PPM):
15 mph - MAX:116 MEAS:99 PASS
25 mph - MAX:91 MEAS:66 PASS

CO(%):
15 mph - MAX:.74 MEAS:.23 PASS
25 mph - MAX:.62 MEAS:.15 PASS

It's especially frustrating because I was so close to passing before, but now those NOx numbers are out of control. I might just bring it to the Volvo mechanic that I trust, but I know it'll cost me money I don't have. I really need the car for work, but if I don't get my smog, I only have until the end of this month until my final extension for my registration runs out.(Incidentally, CA has a program where the state will give you money to help pay for smog-passing repairs, but I don't qualify because I'm trying to register a car from another state. Guess it makes sense.)

Does anything jump out at anybody? Even if your suggestion is, "take it to your mechanic."
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Wine Red 1989 240 Wagon