Help with open loop fault.

[Chrisxb]

I have an ‘07 3.2L. I pulled out from a stop and accelerated and suddenly the car bogged down and started running rough. I got the “slow down or shift up” message then the CEL started flashing. After a moment it seemed to sort itself and the message cleared , but this scenario repeated several times as I limped it home. It didn’t set any codes. After I got it home I left it sit for a day then when I tried starting it it seemed to idle ok but as soon as I revved the engine the slow down message came back and it started running rough. I had my scan tool on it and noticed it went from closed back to open loop. After running it several times it threw codes for misfires on cylinders 1,2,&3. I pulled the plugs and cylinders 1,2,&3 are running rich while 4,5,&6 are fine. The B1S1 O2 sensor was reading very low in the live data on the scanner so I replaced it and it still acts up. The MAF sensor appears to be functioning normally. So if you have ever dealt with this problem I’d appreciate some input.

[chitownV]

Posted a reply in the other forum. What's your service history? How many miles?

Visit this link to see what maintenance you need to do or have missed in your 3.2.
https://www.swedespeed.com/threads/the- ... st-7332383

[Chrisxb]

It has 197500 miles on it. I’ve owned it for about 8 months. The guy I bought it from had the belts changed, new AC compressor installed, and I believe he told me the plugs were new too. Within a few days of acquiring it started throwing codes for threshold efficiency. I ended up buying some cheap converters. In PA you have ten days from purchase to get a car inspected if it is expired or from out of state (I bought it in Maryland) and didn’t have the cash to buy proper converters. They got it through emissions testing but the codes did come back. It was also setting the code for FRP sensor circuit. I replaced the sensor and haven’t seen the code return. However the live data on the scanner shows the FRP steady at 69-70 psi. From what I’ve been reading it appears this should be in the 40s? The only other problem I’ve encountered is the #3 ignition coil gave up the ghost. I’ve been running 5w-30 oil.

[ggleavitt]

viewtopic.php?p=431219 , won't hurt as a reference. If the author is still around, he may be able to chime in.

[chitownV]

It has 197500 miles on it. I’ve owned it for about 8 months. The guy I bought it from had the belts changed, new AC compressor installed, and I believe he told me the plugs were new too. Within a few days of acquiring it started throwing codes for threshold efficiency. I ended up buying some cheap converters. In PA you have ten days from purchase to get a car inspected if it is expired or from out of state (I bought it in Maryland) and didn’t have the cash to buy proper converters. They got it through emissions testing but the codes did come back. It was also setting the code for FRP sensor circuit. I replaced the sensor and haven’t seen the code return. However the live data on the scanner shows the FRP steady at 69-70 psi. From what I’ve been reading it appears this should be in the 40s? The only other problem I’ve encountered is the #3 ignition coil gave up the ghost. I’ve been running 5w-30 oil.

I'm not too far from you here in Maryland.
You really need to go through the 3.2 thread to assess what you need to catch up on for maintenance. All of the things listed below are in the 3.2 thread. You said a lot already and viewing just one piecemeal thing in the fuel isn't going to help. It will involve looking at the overall engine needs for your mileage. This includes understanding why your cats went out at 197k miles because there are a lot of us high mileage XC90 3.2s with good running emissions due to proper maintenance. Most of the time we can trace catalytic converters going out due to lack of maintenance, whether that's doing 7k mile oil changes with non-synthetic oil, oil consumption, delaying changing the PCV, or other known 3.2 maintenance that could affect the operation/fuel/air/spark.

I asked questions in the other forum which would help a lot in understanding your engine's condition. The 3.2 shouldn't burn oil. If it does, it shouldn't burn oil like the older Volvo engines.

For the immediate and near term, these are the things I would suggest:
Oil/filters
- Change the oil to Mobil 1 0W-40. The engine runs better and the thicker hot viscosity oil will help with oil consumption. If you like Pennzoil, you could use their Platinum Euro 0W-40, but for now, the Mobil 1 has a higher amount of detergents which could help over time with any piston ring carbon build-up. You can easily order the Mobil 1 FS (Euro) 0W-40 at Walmart. Oil that passes the piston rings can get into the spark plugs and catalytic converters.
- Use a good oil filter.
- Change the air filter.
Spark
- Don't assume the spark plugs are new. Get the correct ones.
- Ignition coils can go out on any of these engines, especially with approaching 200k miles. Don't go to Autozone for a cheap brand. People have had their cheap coils melt causing more issues.
Fuel
- For the fuel, start with the basics of changing the fuel filter and running a tank of fuel system cleaner (not Seafoam, use a modern one).
- The fuel pressure sensor can go on all of these P2 engines as early as 75k miles. Your call if you want to change it, if you think it could be reading inaccurately, is dirty, etc.
Vacuum/air
- Double-check the intake tubes are tight and not leaking.
- Last, but certainly not least, you might need to change the PCV unit/box. This can cause oil consumption, running issues, O2 sensor readings that are off, etc. Get a good OEM brand, or an original Volvo/Land Rover/FoMoCo one. The cheaper alternative PCV boxes and the diaphragm kit from Dorman don't work well. Their manufacturing is off.

Again, the 3.2 thread. It has a lot of valuable information and collected experience from 3.2 owners and Volvo mechanics.
https://www.swedespeed.com/threads/the- ... st-7332383

Here's a more specific thread on the catalyst, oil consumption, and piston ring carbon build-up
https://www.swedespeed.com/threads/3-2- ... on.658144/

[Chrisxb]

Thanks for the information. I found the cause of my trouble. One of the POS converter’s (bank 1) catalyst disassembled itself and clogged the down stream converter. I pulled it off and looked inside and could see straight through. I know it was not a smart thing to buy cheap no name converters from eBay but as I said I had to get it inspected and didn’t have the resources to buy proper converters. I was planning to replace them before winter set in but I suppose it couldn’t wait that long! I should have been more proactive! When I initially pulled the spark plugs to inspect them I replaced them with a set I bought but hadn’t installed. I ordered a new EGR valve and fuel filter with the new cats. The EGR was way overdue. I changed the oil with 5w-30. Next change I’ll go with the 0w-40. The new cats are working and the O2 sensors are now behaving. I’ve put a few hundred miles on it and the plugs look good so far. I’m still trying to figure out if the fuel pressure is too high but it’s running well.

[ggleavitt]

Should would coulda, know those three quite well. Thanks for the follow up, it's good to know how this ended up.

[chitownV]

Thanks for the information. I found the cause of my trouble. One of the POS converter’s (bank 1) catalyst disassembled itself and clogged the down stream converter. I pulled it off and looked inside and could see straight through. I know it was not a smart thing to buy cheap no name converters from eBay but as I said I had to get it inspected and didn’t have the resources to buy proper converters. I was planning to replace them before winter set in but I suppose it couldn’t wait that long! I should have been more proactive! When I initially pulled the spark plugs to inspect them I replaced them with a set I bought but hadn’t installed. I ordered a new EGR valve and fuel filter with the new cats. The EGR was way overdue. I changed the oil with 5w-30. Next change I’ll go with the 0w-40. The new cats are working and the O2 sensors are now behaving. I’ve put a few hundred miles on it and the plugs look good so far. I’m still trying to figure out if the fuel pressure is too high but it’s running well.

That's great news! It's a valuable lesson that others can learn from if they are thinking about using cheap parts.....almost always it will cost you more in the end if you install cheap parts.

Sounds like you have a good starting plan for maintenance. Keep it up and enjoy your XC90.

[abscate]

I had plugged cats on a bmw that cost me 3k to fix. The cheap ones were $500. My indie had a pile of them in his shop, 1-2 years old, from people who failed inspections and had to replace in short order.

Get a warranty or buy OE only on cars unless you relish pain