Hey guys,

So I need to have my truck etested in less than a month but I know it won't pass with a large evap leak. I'm 90% sure its cause my gas cap or filler neck area.

The CEL was on since I swapped the engines and the last time I filled up it went away, but the code is still there. I picked up a gas cap from the dealer ($29 - blow me) about a year ago and now he problem is back.

It is extremely tough trying to fit the gas cap in the neck, the plastic grabs the side so you kind of have to wiggle the cap in. I personally don't care that its a PITA I just want it to pass emissions.

If I clear the codes, how long until our monitors will read ready? I've checked all the hoses, especially ones running into the evap canister and they look good.

Should I try yet another cap? If I do I'll wanna clear the code since it'll probably still linger. Just don't wanna have yo drive for 2 weeks till the monitor reads ready.

Anyway I can check this myself? Does a normal scan tool read this info?

 

Your fill spout may be bent especially from what you are explaining the cap having problems going on or the spout has a small hole in it.

I have seen a number of people needing to replace them on this forum.

Everyone says go OEM dealer caps only the aftermarket ones don't work so well.

 

Well I'm pretty sure it has to do with the seal on the cap itself. If there was a hole in the neck wouldn't the CEL stay on always? If you fiddle around with the cap then it goes out. But my scanner still shows P0455.

Just priced out another gas cap and it went up a dollar Lol. $30 for an OEM cap.

I'll have a look to see if its bent but I'm fairly certain it's the cap.

Thanks for the suggestion.

 

The code will go away if you re-set the codes using a scanner with about 1/8 of a tank left, go run it out, then fill up, and get tested after burning 1/8 of a tank (or about when the needle actually gets to F). The vacuum pump only runs between 3/4 and 1/4 marks. Mine throws 6 different codes (evap, misfire, coil primary), and this works for me just enough to pass.

 

Magnet,

If I reset the codes this will set the monitors to not ready. Do you have any idea how long it takes for the monitors in these trucks to be ready?

In my province you must have no codes and your monitors must all be ready. If this criteria isn't met its an auto fail.

 

I use my SCT or digital dash display (Ultra-Gauge) to reset mine, and it doesn't reset the ready's that I know of (disconnecting the battery will). Here in texas you're allowed 3 not-ready's and I usually use all 3 to pass. When i unhooked the battery to do mine, it took a couple of city and highway miles to re-set them. That's when I started using the SCT to clear them, and now the digital display.

 

Ahh I'm only allowed 1 to be not ready...

Clearing the codes with my scanner or unhooking the battery causes the monitors to reset.

 

yea, I'll have to find my inspection report and take a pic, I carry it in the truck incase a cop asks how I'm legal (because I'm usually not emissions legal, lol...imagine that).

 

Hahahaha

Well I got home today and plugged in my scanner. Still have P0455 but no CEL. Key cycle shows P0455 too.

My scantool showed all 7 monitors as ready, 0 not ready, and 3 not supported.

There was also an option to test the Evap system which I never noticed before... Not sure what this does but it tells me it passed.

I'm wondering now if I'll get failed even though its throwing a "soft" code - there's a code, but its not throwing CEL.

The fact that the code is emission related leads to believe otherwise...

 

never know till you try. the CEL isn't burned out, is it?