krinkle

This is my first post here, I have lurked here and there before when looking for repair advice. Anyways as the subject says I have a P2195 on my wife's 2008 IS250 with 70k miles.

A little history, some or all might be unrelated to the code but it never hurts to get more information.

About 7k-8k miles ago my wife got a letter from Lexus about rough idle and that she should bring her car in to see if it had the problem, if it did they would fix it. It was stated in the letter that it was not a recall. She had mentioned this to me where the car would be at a stop and for 5-10 seconds it would sound like it wanted to stall. She took it in and they said yes it needs the repair. Took about 2 weeks and I looked at the paper work and it looks like they replaced the PISTONS. That seems crazy to me, but whatever it drove fine and didn't seem to exhibit the problem again. While at the dealer they said you need new plugs (car had about 62k or so) and I opted against it since they wanted $300 for the service.

So about 5k miles ago I figured I'd change the plugs, I've been wrenching on cars my whole life, but never a Lexus. I learned that the passenger side plugs on this car are easy and the driver's side plugs are a PITA that necessitates the removal of the intake manifold. I preformed the service and replaced the intake manifold gaskets during this service. No check engine lights after and car ran fine.

No fast forward to last weekend, we were in car, I was driving and we watching the odometer flip to 70k. Then on our drive home a few hours later, check engine light and "CHECK VSC" on the little LCD. Crap.

So I pull the code with a ScanGuage II and it's a P2195. I clear the code and see if it comes back, yes the next day, same code.

I poke around and it is a Bank1 Sensor 1 lean condition of some sort. Seems like it is often related to the upstream air/fuel ratio sensor. More commonly known as a 4 wire wide band oxygen sensor. So I say screw it and I buy a Denso OEM replacement locally for $150.

I replaced this morning, was a little bit of a pain as it's a tight space, but it is done. Drove to work after about 20 minutes street highway, no code. Drove home, no code. Drove to grocery store, no code. Drove home from grocery store, P2195!!!

So unless I damaged the sensor or I have mixed up bank 1 and bank 2, it's not the sensor.

For clarification bank 1 is on the driver's side, correct?

What should I check next. I was thinking I would check all the bolts for the intake manifold. Replace the throttle body gasket, which I did not do when I did the plugs. Double check all the vacuum lines. Some people suggest cleaning the MAF, but the car has never had any aftermarket parts, ever, so I'd guess it's clean. After that then it starts getting hairy, checking injectors etc.

So can anyone provide me with a logical set of steps from easiest to PITA?

Thanks for any help, this one is frustrating me.

krinkle

Well after some more research I guess Bank1 is the PASSENGER side and Bank 2 is the driver's side. So I changed the wrong one. ARGH!

If someone can confirm this please do.

krinkle

Wow, what an ordeal this has been.

I finally had to remove the passenger side exhaust manifold to get the O2 sensor off. Okay not too bad. Has chase the thread on manifold with a tap, a chase did not work. The factory installed sensor had galled on the first thread and a half.

After double checking everything and carefully torquing the exhaust manifold nuts to 16 ft-lbs. There is clearly an exhaust leak at the manifold. I am going to, for now, blame the Fel-Pro exhaust manifold gasket I used. I tried snugging up the bold a bit more and it help a tiny bit but there is still a leak.

I have now purchased a brand new Lexus/Toyota exhaust manifold gasket. Just for note, I should have known as soon as I took the Fel-Pro out of the box not to use it. It is not built at all like the Lexus/Toyota gasket. The Lexus/Toyota gasket is a 2 layer metal gasket. The Fel-Pro is some type of thick soft metal/fiber thing. I gave it a try and wasted way too much time. Save a penny waste hours, not worth it.

That all said I'm waiting for the car to fully cool down before I pull the Fel-Pro out and install the new Lexus/Toyota gasket along with new gaskets at the exhaust side again from the dealer. I hope to God this solves this issue and I can be done with this frustrating repair.

After this it's getting traded in.

krinkle

Welp, it was that POS Fel-Pro (felpro, FelPro, crap). Just fired it up with a brand spanking new Lexus/Toyota exhaust manifold gasket and smooth like it used to be.

Hopefully this thread helps someone. I'll post photos of the 2 gaskets later for reference.

krinkle

Here is a photo comparison of the factory Lexus/Toyota exhaust manifold gasket and the Fel-Pro garbage edition exhaust manifold gasket. Switching to a new factory one solved my problem. Stay away from the Fel-Pro no matter how desperate you might be.


Fel-Pro top right, Lexus Bottom left


Lexus two layer metal gasket


You can see here where the Fel-Pro leaked, this happened on spots fro each cylinder. Mostly manifold side with a little on one cylinder head side.

You can see more photos of the how A/F sensor debacle here:
https://www.flickr.com/photos/krinkl...7644167126144/

dmanwi

I have been getting the p2195. I checked the previous owner had the o2 sensor changed just in 2014. how can I tell if I have this same exhaust gasket leaking?

krinkle

Sound like you need Bank1 Sensor 1 oxygen sensor which is on the passenger side. If you had a gasket leak you would hear it and it would sound awful. I'd make sure to get either an OEM lexus O2 sensor or a Denso with the factory connector on it (same as OEM just cheaper).

And good luck, hopefully you can get it out without have to take the exhaust manifold off like I had to.

FYI, traded this car in for a Subaru Forester after I was done with this.