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1998 V70 NA Failed Emissions High CO and HC at idle

Help, Advice and DIY Tutorials on Volvo's P80 platform cars -- Volvo's 1990s "bread and butter" cars -- powered by the ubiquitous and durable Volvo inline 5-cylinder engine.

1992 - 1997 850, including 850 R, 850 T-5R, 850 T-5, 850 GLT
1997 - 2000 S70, S70 AWD
1997 - 2000 V70, V70 AWD
1997 - 2000 V70-XC
1997 - 2004 C70

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erikv11  
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Re: 1998 V70 NA Failed Emissions High CO and HC at idle

Post by erikv11 »

Open up the flame trap housing, if the little disc with holes in it (like in the picture up there) is still in place, take the disc out and throw it away. That may help.

Also we are just guessing here. The quickest way to get info on the CV system is to do the "glove test" see if there is positive crankcase pressure.
'95 854 T-5R, Motronic 4.4, 185k
'98 V70, T5 tune-injectors-turbo, LPT engine, 304k, daily driver
'06 S60 R, 197k
'07 XC70, black, 205k
'07 XC70, willow green, 212k
'99 Camry V6 :shock: 153k
gone: '96 NA 850 210k, '98 NA V70 182k, '98 S70 NA 225k, '96 855 NA 169k

evilxsystems
Posts: 22
Joined: 17 October 2010
Year and Model: 1998 v70
Location: seattle

Post by evilxsystems »

Ok. I did the glove test and it failed (ie. the rubber banded glove inflated on the oil cap). I hard reset/drive cycled the computer. The car hasn't thrown a P0172 code since replacing the vacuum line, but is throwing a P0102 code, which it had previously thrown but I had thought was due to my disconnecting the mass airflow sensor at one point, but it came back after I'd cleared the P0172 code, so it seems to be something real. Not really sure where I should go from here???...I'd really like to do something quick to get it past emissions, but I don't think I can tackle a PCV rebuild myself in the middle of the week. Is there an easy way to pull the flame trap housing off the rigid airtube without disassembling too much, to try to clean it, to see if that helps enough?

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erikv11  
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Post by erikv11 »

PCV is a pretty long job, you are probably on the mark in your assessment there. I can't think of any shortcut to dealing with the flame trap, you have to take apart a few things (accordion intake hose and airbox both come off pretty easily, that should make enough room to get in there and open up the flame trap to throw away the disc).

P0102 is most likely another vacuum leak, get vac leaks all sorted out before you go chasing MAF demons. Similarly, the car can pass emissions with a clogged PCV, but probably not with vacuum leaks.

There is danger of blowing out the rear main seal if the car is run a long time with clogged PCV. You can relieve the issue until you have time to repair it by relieving the pressure - pull the dipstick up just a hair so it can vent. But beware this can throw oil out of the dipstick tube. Showing up to the inspection with the dipstick out would probably lead the car to fail emissions too ..
'95 854 T-5R, Motronic 4.4, 185k
'98 V70, T5 tune-injectors-turbo, LPT engine, 304k, daily driver
'06 S60 R, 197k
'07 XC70, black, 205k
'07 XC70, willow green, 212k
'99 Camry V6 :shock: 153k
gone: '96 NA 850 210k, '98 NA V70 182k, '98 S70 NA 225k, '96 855 NA 169k

tryingbe
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Post by tryingbe »

I'd say you'll need a catalytic converter too. Not sure what the laws are in Seattle, it's $80 for a mangaflow cat and then labor to install here in AZ.
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00 Insight, 72 mpg

benpineapple
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Post by benpineapple »

What's the state of your O2 sensors? Your car has 2 O2 sensors, and as I understand it the rear-most one mostly is used to control emissions or something. Just a hunch.

With emissions reading that high, it could be a slew of things going on. I agree with everyone else though, PCV system (while not easy task) is likely one of the main culprits here. No easy fix/silver bullet for fine-tuning and emissions.
2006 V50 T5 [190,xxxM]
2013 XC90 FWD [80,xxxM]

2001 V70 X/C AWD [sold at 120xxxM],1998 V70 AWD [RIP at 249,255M], 1990 240 [SOLD at 220xxxM]

evilxsystems
Posts: 22
Joined: 17 October 2010
Year and Model: 1998 v70
Location: seattle

Post by evilxsystems »

benpineapple wrote:What's the state of your O2 sensors? Your car has 2 O2 sensors, and as I understand it the rear-most one mostly is used to control emissions or something. Just a hunch..
I believe (need to double check) that both O2 sensors were replaced about 60,000 miles ago.

evilxsystems
Posts: 22
Joined: 17 October 2010
Year and Model: 1998 v70
Location: seattle

Post by evilxsystems »

benpineapple wrote: With emissions reading that high, it could be a slew of things going on. I agree with everyone else though, PCV system (while not easy task) is likely one of the main culprits here. No easy fix/silver bullet for fine-tuning and emissions.
It seems weird to me that the cruising emissions would be fine though, it totally passed at 2500rpm, which makes me think it's still a vacuum problem.

evilxsystems
Posts: 22
Joined: 17 October 2010
Year and Model: 1998 v70
Location: seattle

Post by evilxsystems »

tryingbe wrote:I'd say you'll need a catalytic converter too. Not sure what the laws are in Seattle, it's $80 for a mangaflow cat and then labor to install here in AZ.
:D how in the hell do you get a CAT for $80?!? the stock one is like a grand! Platinum is fucking expensive, I can't see how they can do that. But I'm sure replacing or cleaning the cat would help, but I'd thought it would be crazy expensive. How hard would it be to pull off the old cat and install a non-OEM one? It's the original cat, I've heard they get so hot that they can be basically welded on.

evilxsystems
Posts: 22
Joined: 17 October 2010
Year and Model: 1998 v70
Location: seattle

Post by evilxsystems »

erikv11 wrote:PCV is a pretty long job, you are probably on the mark in your assessment there. I can't think of any shortcut to dealing with the flame trap, you have to take apart a few things (accordion intake hose and airbox both come off pretty easily, that should make enough room to get in there and open up the flame trap to throw away the disc).
Ok, that's easy enough...I'll try that this morning

As far as tracking down other vacuum leaks, are there any other hoses that are especially problematic? The rubber elbows on the lines coming from the vacuum tree are pretty degraded...I can replace those lines without too much effort..Could the vacuum solenoid valve fail and cause this?
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rspi
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Post by rspi »

Come on guys, give him the magic answer. You guys know that no one wants to do the proper maintenance. Why else would he have paid top dollar ($4000) for the car. In the time that has been spent chasing this post, the system could have been replaced. It literally can be done in 2 hours on a NA car.
'95 855 T-5R M, Panther - 22/28 mpg, 546,000 miles
'95 955 T-5R Yellow Wagon, Lemonade, 180,000 miles
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