Extremely Rare P0455

JeffHicks · Post by **JeffHicks** » 30 Sep 2014, 15:08

99 v70 base...

A little over a year ago, my CEL flipped on and gave me the P0455 code - basically a vacuum leak detected. I inspected everything, and found a hole in the J-Tube, by the charcoal canister, so I replaced it. I found no other leaks of any kind.

Since then, it has thrown the P0455 code twice. I'll clear it, and there will be no code for months. Then, out of the blue, it'll show up again. It won't be during hard acceleration, or wet conditions, or anything similar. Completely random, as far as I can tell. Performance & mileage doesn't seem to be affected at all.

Is this purely random, or is it a tiny vacuum leak that'll eventually get worse? Something else? Any ideas?

Post by **abscate** » 30 Sep 2014, 19:11

It's not that you fixed it, it's taking 1000 miles plus for the evap circuit to go ready and then re trip the CEL!

Evap codes on the P80s are pesky buggers , check all those hoses carefully

Post by **JRL** » 30 Sep 2014, 20:40

Smoke test the lines
That's the ONLY way to find it, since it's not obvious

Post by **850 LPT** » 01 Oct 2014, 05:58

JRL wrote:Smoke test the lines
That's the ONLY way to find it, since it's not obvious

The exact same thing is happening to mine. And I had mine smoke tested about 6 weeks ago, it checked out fine. The code came back last week.

Post by **mecheng** » 01 Oct 2014, 07:09

My j-hose was fine, so I swapped out to a new gas cap. I reset the ECU so I am patiently waiting to see what happens; it does take a while for the code to appear. It took 5 months for me.

I've heard that the Purge Valves on these cars often fail, that would be my next guess without a smoke test. Although I may just take it somewhere to get it tested that has a smoke machine.

Post by **abscate** » 01 Oct 2014, 07:11

There is a resistance spec on the purge valve solenoid of about 20 ohms as a first test, I believe. I think I put that into a thread on my 1999

Post by **rmmagow** » 01 Oct 2014, 11:05

Does a 99 have the shut-off valve? Mine is buried under the front fender. Doesn't the j-hose connect to the shut-off valve? My 98 will go ready on everything and go for months before popping the P0455 again. I've heard that reading with the dice tool will give a more specific indication of what tossed the code.

Post by **regent** » 01 Oct 2014, 12:23

rmmagow wrote:... reading with the dice tool will give a more specific indication of what tossed the code.

Yes, it will (to a certain point), and in addition, there are several component tests available in VIDA.

Post by **abscate** » 02 Oct 2014, 13:08

rmmagow wrote:Does a 99 have the shut-off valve? Mine is buried under the front fender. Doesn't the j-hose connect to the shut-off valve? My 98 will go ready on everything and go for months before popping the P0455 again. I've heard that reading with the dice tool will give a more specific indication of what tossed the code.

My 1999 (late CY 1998 build) has the evap canister, rollover valve, and shutoff valve mounted just in front of the right rear wheel. It is a drag to get under there to check these components out, but car on ramps or jackstands is doable.