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typical Ranger emission test failure?

Old 03-06-2010
allstateguy's Avatar
Thread Starter
Join Date: Mar 2010
Location: Phoenix, AZ
Posts: 41
typical Ranger emission test failure?

95 4.0 2wd w/81k miles
Well the tailpipe portion of the IM147 went fine, about half the limit in all three areas.
BUT, the gas cap/evap system test failed.
Is there a typical area on the Ranger that causes this? Is there a known fix?
Old 03-09-2010
Join Date: Jul 2007
Location: Lancaster, CA
Posts: 277
I Don't know this test here in smog **** heaven they just test the gas cap. If it fails they will sell you a new cap usually at a premium price or pay for a new test. How is the evap system test done?
Old 03-10-2010
allstateguy's Avatar
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Join Date: Mar 2010
Location: Phoenix, AZ
Posts: 41
They do test the cap to see if it will hold pressure. Mine failed that too, but like you say, just buy a new one.

The evap test pressurizes the tank, fuel filler neck, vapor hoses going up to the engine from the tank, the charcoal canister and the canister purge valve. This is all to make sure gasoline fumes don't get out.

In my quest to get it fixed, I took it to a shop who said "Oh yeah, it's the filler neck hose, which rots out on all Rangers. You can't just replace the hose, you have to replace the whole filler neck. It costs $450+ just for the part from Ford"

Well, thanks for the diagnosis (free) and I took the truck home.

I went on eBay and found a place that sold the filler neck (probably made in China, maybe better quality than the original!) for $45 shipped.

It is sitting on my toolbox now, I hope to install it tonight (AllData says .6 hrs) and get the truck retested. Yay!
Old 03-10-2010
Rolldogg's Avatar
Join Date: Jan 2006
Location: Ottawa, Ontario
Posts: 3,424
The gas caps are pretty cheap too, both in rice and construction. My original gas cap broke and I couldn't open it to refuel. I replaced it with another OE one, but every now and then if the cap isn't closed properly or tight enough, the CEL throws a code for a minor leak.....I believe it's P402 or something.
With the filler neck replaced and possibly a new gas cap, your truck should pass the test.
Old 03-11-2010
allstateguy's Avatar
Thread Starter
Join Date: Mar 2010
Location: Phoenix, AZ
Posts: 41
well changing the filler hose fixed the problem. Passed emissions and has plates now. BUT getting the old hose off was a total byotch. Had to take the bed off (no problem right?) except there was this 300lb bottle of CNG bolted to the front of it. Thank god for strong friendly neighbors. SO EASY with the bed off.
Old 03-11-2010
Join Date: Mar 2007
Location: Upstate,NY
Posts: 2,598
One other problem spot is the purge valve. They tend to "stick" over time .
Usually it will throw a code.
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