99 S70 T5 - EVAP or O2 sensor?

evenBIGGERrock · Post by **evenBIGGERrock** » 05 Nov 2007, 14:35

New to the gang here. Lurked a few times looking for other stuff, but have run into one I'm not quite sure of.

Have something like 105k on the clock. Recently I had the coil on #2 go out on me. It went while I was sitting in line and idling. I managed to get it home, roughly 1.5 miles away. I was certainly dumping a lot of raw gas out the exhaust since I could smell it. I'm sure the cat was cooking. Interesting enough it only threw a pending code, and didn't trip the CEL.

So I replaced the coil. Engine starts and runs fine. But now I've got some new problems. The CEL comes on and I get a slew of codes. I've tried clearing them a couple times just to see if driving it for a while may clear them up, but no go...they are for real and here to stay. They're a little inconsistent and don't necessarily all get registered at the same time, but here's what has managed to show up almost every time I've cleared them (all P codes):

1655
0445
0448
0245
0031
0037

I know what the definitions to all of them are, so I'm not looking for a "what do these mean".

They are all related to either the EVAP system or O2 sensors. I checked all the wiring and vacuum lines, all looks good. Sometimes on something like this I'd start throwing parts at it until problem is fixed, but in light of the cost of said O2 sensors..............ouch.

Should I just start with the O2 sensors anyway in light of the mileage? Any thoughts on the likely hood of having cooked my cat? Any suggestions on the EVAP system, or are these codes possibly just fallout from O2 sensor problems. Could the problem lie some place else all together?

I'm leaning on the O2 sensor side of things simply because I know a lot of raw gas went out the backside. Anyone else experience anything like this when a coil goes bad?

Post by **MadeInJapan** » 05 Nov 2007, 15:39

A dirty MAF can cause false O2 readings...go with the cheap first and try cleaning the MAF. If that's not it, you are at the miles that the front 02 starts to go....what troubles me is that most of the time it's a slow degradation with poor gas mileage...not what you describe. Although I've had a MAF go instantaneously.

evenBIGGERrock · Post by **evenBIGGERrock** » 05 Nov 2007, 17:20

thanks for the idea. I'll give it a stab and report back.

tripleb · Post by **tripleb** » 05 Nov 2007, 17:57

If you have an evap valve stuck open, it can be like having a vacuum leak.

You can disconnect the connector to the evap valve while it is idling, pull the hose off the valve, the one that goes to the charcoal canister, and there shouldn't be any vacuum passing through the valve.

Also, are you sure the codes are erasing?

After you erase them, turn the key on but don't start the car, and check that there are no codes. Just to be sure!

B

evenBIGGERrock · Post by **evenBIGGERrock** » 06 Nov 2007, 23:51

Looks like I'm in for some $$. Cleaning the MAF didn't do it.
I cleaned the MAF then cleared the codes. Started it up in the driveway and it took all of about a second for the CEL to come back on. Shut it off and read the codes back. At this point I did only get the EVAP related codes (and the wastegate solenoid...p0245 as listed before). Then I took it for a little drive. When I got back, the O2 codes were back. Looks like I'll be coughing up some coin for O2 sensors for starters. I'll have to look harder at all the EVAP components as well.

Post by **MadeInJapan** » 07 Nov 2007, 05:38

The evap valve mentioned above is located on the driver's side up against the fan shroud and has a vacuum line going into it and another coming out.

evenBIGGERrock · Post by **evenBIGGERrock** » 07 Nov 2007, 09:58

Yeah, I'm thinking this weekend I'll have to clamber around to take a closer look at every vacuum line, fuel connection, etc.

redwagon · Post by **redwagon** » 09 Sep 2012, 06:46

I just got the same problem with my 99 XC70 B5254T with 135K miles. I had 2 misfire codes (P0352 and P0301). I replaced all 5 spark plugs with Volvo plugs and one new coil. While I had all of the plugs out, I ran a compression test. In the cylinders that had low compression I added a tablespoon of oil into the cylinder as instructed in my Haynes manual to determine if rings were bad. Now the misfire codes P0352 and P0301 are gone and car runs and idles fine but I now have these codes:

P1655
P0445
P0448
P0245
P0031

While I was replacing the coils I accidentally mashed a coil wire under the bolt while tightening but this has been spliced/repaired and spark is fine. I do not think this is related to the codes.

I have cleared the codes twice. When I turn the ignigtion to the ON position, the Check Engine light is off and the car will not start. I turn the key off then on again and the CEL comes back on and the car starts and runs fine.

So I am almost sure that I had a lot of unburned motor oil that got out of the cylider and went downstream. I use syunthitic oil.
The question is: will the contant running of the car fix this or have I permanently contanimated things like O2 sensor; EVAP system (which I do not know much about); turbo wastegate solenoid? Did evenBIGGERrock find the problem?

byeboy · Post by **byeboy** » 09 Sep 2012, 07:06

I really do wish every 'problem posted' would take the time to explain what the final solution was...no matter what it ultimately was...it just leaves all us sleuths hanging...but this post is only five years old...perhaps he's still checking vacuum connections...(there are a lot of them, y'know!)...

Some times the story ends with selling the car, scrapping it (!!), or parking it in the back yard...but we'd sure like to know the ultimate decision, even if the problem never gets solved.

redwagon · Post by **redwagon** » 10 Sep 2012, 18:33

So my problem was:
Blown 20A fuse in the main panel. The fuse is for "Emission System". This must have blown when I caught one of the coil wires under the bolt when tightening it. I replaced the fuse, started the car and the codes were still there. I cleared the codes, restarted the car and the Check Engine Light is now off.