Havea 97 NA 850, w/ 171k, been running o.k., except for blown suspension and brakes that need to be redone, but that's unrelated to my latest problem.

Car has been running o.k., except for above, howeverabout 2weeksor so ago the check engine light came on, pulled the code, P0422 Main Catalyst Efficiency Below Threshold (Bank1)

I reset it, car still running fine. Late last week check engine light came back on, but still running just fine.

This past weekend the car sat for 3~4 days while I was away. Came home took it for a spin, started o.k., ran o.k., about 4 miles down the road I noticed a slight hesitation.Stopped at astop light, proceeded at the green and now the car really was bucking and hesitating and finally just died. I managed to pull it over.

Symptoms sound similar to those decsribed in this thread;
https://volvoforums.com/m_130371/tm.htm

Car would crank but not start. I checked fuses 1 & 2, for fuel pump and ignition, both fine. I could hear the fuel pump start to hum when I turned the ignition key before I would turn it all the way to engage starter. Sounds like it was functioning normally. Once every 8~12 attempted starts I might get a very brief cough.

After sitting awhile the car started, a little rough, but not terrible, then smoothed out somewhat. I could rev the engine in neutral no problem. As soon as I put it in gear it died again and could not get it restarted.

Had it towed home. After several hours I went back outside to the car, started, but was running rough, put it in gear to drive it into the garage and she was running very rough, but was able to get it into the garage.

Checked the OBDII codes again, same P0422.

So I'm somewhat doubtful that the P0422 code is the real culprit to this problem, maybe, don't know?

It's been ~35k since the last tuneup. Maybe it's a simple as cap, rotor, & plugs, but hoping you folks might be able to give me some troubleshooting tips to locate the real culprit before I start throwing parts at it.

Thanks

 

Do the tune up...see if it helps, butI would look into geting a new cat.

 

Is that one code the only code stored? We had a similar issure with our 95 when the coolant temperature sensor went bad. Mad the car think it was running rich, so it leaned out the mixtuire and it would die as soon as we put it in gear. Just a thought.

 

Hmmm..... coolant temperature sensor you say?Interesting idea. When the car was cold it appeared to run fine. Once it got warm after driving down the road is when the problem first occurred.I then could not get it restarted except for a brief period. After sitting in the driveway for several hours I was then able to restart it, although it was running rough, but it did not die when I put it into gear, long enough for me to get it into the garage.

I haven't begun to look yet, but where is this sensor?

Thanks,

 

Forgot to mention, yes that is the only code stored, no other codes to retrieve.

 

Here you go:

 

Nice graphic, thanks.

Latest update. Went out to the garage tonight after work to see what I could find. Coolant was down to the bottom of resv so I added some.

Car started and ran just fine. I took it for a spin around the block 3 times. Couldn't get it to reproduce the problem at all. I checked under the plug wire cover, very small amount of oil near the oil filler cap. Another problem for another day. Wires were all snug and dry.

Little bit of crusty oil around base of distributor cap body where it meets valve cover. Almost looks like any oil that's weeping out near filler cap is following little channel in valve cover and going towards distributor.

Anyhow car ran like a top. While I was out there I cleaned the battery terminals andtopped off the battery water. Dumped a jug of Techron in the tank and I'll drive it to work tomorrow and see what happens. I'll probably order a tune up kit from FCP tomorrow as well.

The only thing I can think of at this point is the car sat outside for 4 days in the rain without moving. The car has been outside for 5 years without issue, but would usually get used every day so maybe sitting for 4 days in the rain caused some moisture to build up somewhere.

I cleaned the windshield cowl drains. One was clogged, passenger side, driver side was fine. I did recently replace the blower motor and resistor and also put in a cabin air filter, which requires removal of the windshield/wiper cowl. All went without issue however I did notice the foam rubber ring under the driver side wiper shaft doesn't quite seal 100% to the plastic cowl. Not sure if it ever did. It appears any water that gets past the plastic cowl would go into the dash cavity underneath and the next drainainge system down there. When I did check the main fuse compartment yesterday it was dry with no sign of moisture or condensation.

I guess we'll see what happens tomorrow.

Thanks for the suggestions.

 

Cool good luck

 

>I'll probably order a tune up kit from FCP tomorrow as well.
That is a nice touch.

In case if you like to test the ECT sensor, see attached.


JPN

[IMG]local://upfiles/6892/03CE07DEC5B744EFB45787AF2903B79F.jpg[/IMG]

[IMG]local://upfiles/6892/2459F266FFBB4840804B6EE6073D310A.jpg[/IMG]

 

Thanks for the replies. Been driving the car for the past 2days without issue, tune-up kit from FCP should be arriving shortly. So maybe it was just weather/moisture related, or some crud in the gas. I'm getting a new fuel filter with the above kit for it's time for that as well.