Fixing P1443

Above: 1996 Ford Escort 1.9L Evaporative Emissions Purge Valve

Several small wins today culminated in a successful replacement of a part that may or may not have contributed to my car exhibiting the P1443 Check Engine code:

• Found the service information for the $25 purge valve part that I researched in my car's service manual. The Helm service manual contains 3,000 pages--it's 3 inches thick and measures a foot on each side. Ford organizes their service manual index by sub-system (for example, Engine, Electrical, Exhaust), which rules out a simple alphabetical search. I finally found it under the Evaporative Emissions (EVAP) section, which makes sense, retrospectively.
• Purchased the part: Brought the service manual with me to NAPA Auto Parts and showed them the part. It turns out I needn't have done that--they have a computer that can look up parts based on the car's year/make/model/engine. They had the appropriate part in stock and I purchased it for $26.
  
• Found the location of the part in the engine compartment. It turns out that the service information for the purge valve states that the part lies beneath another part, the engine air cleaner part. It doesn't list what page the engine air cleaner part is on though. So it's back to the index--is engine air cleaner under Engine? No. Several iterations of this later I discover it under another sub-system whose name escapes me. Perfect. I can't see the part yet, but I know it's under the box containing the air filter, something I have some experience with.
  
• Removed the engine air cleaner part. The engine air cleaner connects to the chassis with two bolts and a retaining nut. It turns out the retaining nut had rusted a bit, and as I loosened it, it made a noise that sounded like something bad was about to happen. I used WD-40 on the bolts and retaining nut to see if it might help. After I removed the other two bolts, I returned to the retaining nut and decided it was now or never, and continued to hear the strange, staccato metal-on-metal noise as I loosened it with a great deal of force. After a few iterations of this it began loosening smoothly--success! The air cleaner removed, I found the purge valve part easily.
• Removed the purge valve. Removing the vacuum tubing from the purge valve represented a new experience for me, and I ended up using pliers to do it since I couldn't get my hands in the right position. A moment of panic struck me as I tore the tubing on one side as I removed it from the purge valve. After a moment of thought, I realized there was enough slack in the vacuum tubing that I might remedy the situation by trimming off the torn section. Whew.
  
• Installed the purge valve. No problem
• Put everything back together again. No problems.

Whether removing the battery ground cable cleared the code, or whether replacing the evaporative emissions purge valve fixed the problem, the Check Engine light no longer displays.

I'll know for sure in another couple weeks whether the fix worked. Until then, everything's running as it did before replacing the part.

For those of you wondering what this little part does--it's part of a sub-system that traps the fuel vapor from the car's gas tank and delivers it to the engine where it's burned off. The valve opens and shuts to allow vapors through. There's another part, the EVAP cannister, that's filled with charcoal that sits between the purge valve and the fuel tank and acts like a odor filter (I think?) . The final part in the sub-system is the EVAP sensor--that's the sensor that trips the Check Engine light when things get out of balance--a plugged/crimped vacuum tube, a faulty purge valve, or a faulty EVAP cannister. Fascinating stuff.