2007 XC90 3.2l torture device

[chitownV]

Sounds great!! Good diagnosis and some simple things after using good parts.

Something to consider. If your XC90 doesn’t have 336mm front calipers that came with the 7-seater option, and/or has any history of not changing the brake fluid for years, it might be a good time to replace the front calipers to larger 336mm reman units.

Me and a few others reported how braking force improved after replacing the old calipers. I didn’t think it would at first, but guess there was more corrosion internally than I thought. Plus, the pad brackets can wear grooves at the pad ear contact points and you won’t have to deal with a potentially seized bleeder screw that breaks off in the caliper.

Good luck with the rest of the work

[rssherwin1]

Yea, mine came with the 336mm rotors from the manufacturer but I don’t have the third row. When I did the front breaks I found out they had different rotors after buying the wrong ones thankfully they let me return them after being opened.

[rssherwin1]

Well here we go again I’m beginning to loose faith in this XC90. Every year right at time for an inspection sticker bam the dreaded check engine light.

OK so I have a week to fix it and drive 150 miles before my inspection sticker expires meaning I can get a ticket after the end of the month.

Here goes the car runs and drive great with the exception of the pesky P0174 code that shows up every year about this time. No other codes have popped up I re-smoke tested the engine no leaks anywhere that I can find. I changed the fuel filter on the off chance that that could be causing it. Nope that’s not it either. PCV was changed completely valve cover with OEM part before last years episode. Please help I think this car has a curse.

I would have made a new post on this but for some reason the site goes to a blank page when I tried so I just added it here.

[Krons]

Just thinking of time of year comment. Cold where you are? Potential O2 sensor getting fouled from the engine mapping running richer in cold temps? Assuming no vacuum leaks.

[chitownV]

You just smoked tested, so this might not apply. Since most of the country recently experienced the Arctic cold, the first thing I would suggest is double-checking the intake clamps and hoses for any looseness.

• Also, double-check the bolts to the PCV. They can come loose.

• If you had VIDA or a better scanner, you could see the live data comparing the Duralast MAF you have against the original MAF. This could still be an issue.

• Did you check the exhaust manifolds and downpipes for any leaks? Even though pre-combustion leaks can contribute to a lean running issue, post-combustion exhaust pipe leaks could contribute to a lean reading.

• One other suggestion, run a tank of dedicated fuel system cleaner, not Sea Foam.

Good luck!

[Krons]

the Duralast MAF you have against the original MAF. This could still be an issue.

Good suggestion.

[rssherwin1]

Well my son drove it last night ran it up to 90 mph and the code cleared. Since then the code has not returned. I got a gremlin I’m sure of it, he’s hiding under the hood waiting to mess with me.lol. Regarding the cold weather I’m in South Louisiana but yes it was 9 degrees and 12 inches of snow for 3 days. Do you have a suggestion for a good fuel system cleaner? I’ll double check the bolts and the exhaust when I get back home on Thursday. I’m currently out on a work trip. Son did run the scanner though and there are no codes pending or registered so maybe it’s a dirty injector due to bad gas? IDK but after he ran it up to 90 maybe it pushed the trash out of the injector it was in just thinking

[chitownV]

So, you’re saying there’s a chance….that a fix is near.

Wide Open Throttle
My first thinking is that the Italian tune up cleared something. Then the mechanic thinking, thought how needing to push the engine at wide open throttle puts the ECU in a fixed program table and ignores the O2 sensors. If the engine is running lean, this could have gotten the catalytic converters hot enough to be more efficient. Cold catalytics are less efficient. Too hot and the precious metals may get affected.

Related to ignoring sensors, a dirty or poorly reading MAP might do the same thing. Or the MAP is reading correctly and there is a vacuum leak somewhere.

Keep an eye out for the codes as it may need a certain number of cycles to trigger the code again. In VIDA, you can see the history of the codes and a snapshot of the running parameters when a code was triggered.

Fuel Injection
I don’t believe driving 90mph would push something out of a stuck injector. As far as which injector cleaner, each person has their preference. The newer fuel system cleaners may have PEA, which helps with carbon. Since the gas tank is large, read the back of the bottle of how many gallons it treats. If it says something like 10-21 gallons, you can keep the tank at 3/4 full so the detergent is a little more concentrated. Also, it might be a good idea to drive more gingerly with a bottle of fuel system cleaner in the tank.

Discounted rate
I’ve hit the XC90’s limiter before and had another fun thought. Your son said 90 mph. Young people report speed at a discounted rate to parents, lol. What is the standard mph add-on to their self-reported speed?