2010 Kluger possible intake leak

[Turbo Taxi]

Hi guys

First time poster here.  Bought a 2010 Kluger Altitude AWD a few weeks back and am loving it so far.  It is my first ever Toyota, with my other car being a BA Falcon XR6 Turbo.  Located in ACT.

Back about a week ago, I got a CEL and VSC off on the dash.  Initial code scan showed P0174 (Bank 2 lean) however now I am getting P0171 (Bank 1 lean as well).  Have also noticed that fuel consumption has jumped by a couple of L/100.  With the XR6 I try to do as much as I can on the car myself short of opening the engine or transmission, however given the relative newness and value of the Kluger, and our reliance on it for interstate trips, I'm intending to drop the oil at the 5k mark between services but in general keep the professional service history intact!

I'm also in the boat of trying to find a new mechanic as the several I have tried since moving to Canberra have been average - stripped diff plugs, wrong spark plugs installed, an inability to set the timing on the EL XR6 I has previously, not refilling brake fluid after removing some to machine rotors.  I could go on!

So back to the issue - I'm keen to get any thoughts on this issue so that if it is a simple fix I can try it myself or at least I am more informed when I go to the mechanic.  Info/my assumptions so far:

 

If I clear the codes, they come back within about 20km (presumably they stay off for a bit because they are referencing long term fuel trim)

Long term fuel trim readings on both banks is around 30, so its adding a ton of fuel to compensate for the issue

120k service on Friday - new mechanic tightened a few hoses to see if it helped.  Service included new air filter.  Problem persists.

I cleaned the MAF sensor Friday night, problem persists.

I am thinking in the intake leak direction as the code is coming on for both banks - if it was just one then an O2 sensor would be in the mix too but seems unlikely given both banks are lean.

Ditto blocked fuel injector - would be unlikely to impact both banks.

I guess fuel pump/filter/pressure reg could be an issue - should be simple enough to get the mechanic to check fuel pressure to the fuel rails

I did just find a small vac hose that was cracking at the ends.  Didn't look like enough to be an issue, but swapped out for some new hose so will see if that helps.  I'm a bit tempted to grab a couple metres of hose and just change them all.  Bit surprised that most of the lines don't have clamps, but I guess on my other car some of them build positive pressure rather than just varying levels of vacuum.  I've had a good dig around the various lines and on visiual inspection at least, everything seems in place and connected OK.

I wonder too re the intake manifold gasket - this was presumably changed when the spark plugs would have been done at 100k.

I should just let the mechanic do his job I guess, but if my intake leak assumption is reasonable, a smoke test is probably a good place to start.

Any thoughts or experiences you have most welcome!  And thanks for the forum - was some good pre-reading while I was on the hunt for a Kluger.

 

Cheers

Andrew

 

 

[trentmeyer23]

The O2 sensors could be fouled a well. You could pull them out and give them a hit with some brake cleaner. It may or may not work, but it is quick and relatively inexpensive to do.

[Turbo Taxi]

Thanks, I'll take a look at them. It's annoying that for everything I try it needs quite a decent drive before I know if it's worked or not!

[trentmeyer23]

Does it affect perfomance in any way?

[Turbo Taxi]

I don't think so - although I have only had the car a couple of weeks so don't have anything to compare it to. Certainly no rough idling, misfires, etc.

[Turbo Taxi]

Just reporting back where this one got to - the mechanic could fit me in yesterday so I didn't get a chance to try cleaning the O2 sensors first.  He ran a bunch of tests - checked exhaust gas against what the O2 sensors were reporting, etc.  Found MAF signal voltage was low, so removed this and cleaned it.  Voltage picked up (from around 0.2V to 4V) and they then ran the car for a while while logging data and all air and fuek indicators were good.  I did a reasonable amount of driving yesterday, that was pretty representative of my usual driving conditions, and no CEL and fuel economy seems to have improved by about 20%.

When I check the Long Term Fuel Trims with the Torque app, they are still up in the 20s and I would have thought they should be around zero (which I also confirmed in the BA).  However my understanding here is limited, and given that the CEL is staying off, and the economy has improved, I should just move on!  Given the impact that servcing the MAF had, if the problem comes back I might consider just swapping out the MAF straight away with a new one or a known good one to see what happens.

[Turbo Taxi]

Aaaaaand... the lights are back on. Maybe my suspicions about the LTFTs were right. Same codes for lean banks 1 & 2. I can't hear any hissing etc under the bonnet to suggest an air leak, but it is cheap I suppose to replace the vacuum lines. 

Any other thoughts? 

[trentmeyer23]

O2 sensors, if not cleaned/checked already.

[Turbo Taxi]

Thanks. Mechanic said they tested perfectly (comparing their results to gas analyser) but no harm in me giving them a clean. 

[Turbo Taxi]

Thanks again for this.  I tried cleaning the bank 2 sensor as it is easy to get to, but made no difference.  Booked the car in for another look, and then the night before the CEL and VSC lights went off!  Checked the LTFTs and they have dropped to about 15% - still not good but obviously within the envelope for the car throwing codes.  Mechanic checked the car over fully again and said everything seemed great.  

I spoke to another place for a second opinion, who suggested it was almost certainly the O2 sensors and that it is surprisingly common that they fail together at a certain age.  He suggested I throw some new ones in - if it doesn't fix it, well they are well and truly through their useful life anyway.  Car has 120k on it.

I've ordered two pre-cat O2 sensors from Bosch which should arrive early this week.  Bank 2 (closest to rad) is easy of course.  Anyone got any experience changing sensor 1 on bank 1?  I have had a look and think I should be able to *just* get an O2 sensor socket and ratchet handle on it from underneath, but I can't see the wiring connector at all.  I'm wondering if I remove the piping from the airbox to the throttle body whether I will be able to access the wiring from that direction.