Failed emissions due to fuel cap??
 

At at 36k miles my fuel cap failed the seal test during emissions testing. The cap does not throw any codes though? Does anyone else have a problem with their fuel cap?

Check the cap o-ring for any small tears or folds. That's what usually causes a cap to fail. They are also pretty cheap too, I'm not sure if the Z's are as finicky as Honda's are, but I would go OEM.

I'm going OEM. It's only $25 with my employee discount. I just find it odd that it would fail at 36k miles. My old 240sx had 200k+ and didn't have any issues >:/

Could it because of Ethanol base fuel.?Rubber Parts worn off fast...

huh, how does a fuel cap fail if u didnt have a dtc? :confused:

That's what I told the guy! In TN they take the cap and hook it to an adapter which I assume has vacuum applied to check for leaks? They did try several times before they gave up so maybe it is on the verge of failing and throwing a dtc? I'll buy a new OEM and if that fails then I'll assume operator error from the tester.

thats a new one on me, vacuum on the gas filler...they dont even do that here in CA that Im aware..

yah, dat sounds 150% dumb.

May be pressurized? Never failed for fuel cap before so it never really bothered me until now :confused:

I went through 2 on my '04 G35, they were the cause of a code tho...

They do it here in Colorado too on the older cars (pre 2012 I think), I had to do it on my cars before the Z. Most likely operator error on that but those guys aren't really the top of class techs anyway.

I can agree with this statement. The guy asked if it was a 350z... Then he asked if all of them came with targa tops... They did make an attempt to test the cap 4 times so they get an A for effort...

probably covered under the emission warranty....

The other way around; later generation cars are generally equipped with hardware that are more resistant to ethanol. A 200SX (FWD and RWD) predates Z34; the RWD version by decades.