81corolla

2000 RX 300 AWD, 83200 miles

I changed the automatic transmission fluid on Saturday. I just did a drain and refill. No problems. BTW, great guide TunedRX300.

I decided I'd reset the "adaptive transmission" - pulled EFI fuse.

Sunday driving - no problems.

Monday evening CEL came on. Not sure what the problem is but stop and check ATF fluid. All's well w/ATF fluid level and no problems there. So pulled EFI and ECU fuse to reset CEL.

Today, Tuesday, CEL goes on again. Say ~20 miles driven since yesterday's reset. Take it to AutoZone to read codes: P1130 (bank 1 sensor 1) and P1150 (bank 2 sensor 1).

I regret pulling the EFI fuse to begin with 'cause now it's confused. :-(

The printout from AZ says:
Before I bite the bullet and buy new A/F sensors I want to verify what I should check:

a) Air hose from air filter - did it pop loose?
b) MAF sensor - clean it
c) AF sensor wires are snug
d) Vacuum hoses - where do they run?
e) I do track my MPG. Seems a little low ~16 MPG, but it's been cold, so hard to say there's been a definitive drop in MPG
f) ??? - anything else to check?

I find it odd that the ATF change would cause the CEL. I suspect pulling the fuse is the more likely culprit.

Also, is there any harm to driving with bad sensors aside from poor MPG?

Thanks.

Lexmex

Reset it again, this time with the battery. Having double, on both a/f sensors, could be just some bad gas (or even down here bad air) and it may need to pass through the system. There is something else that can cause a double a/f sensor cel, and that would be shotty piston rings, basically bad compression, allowing oil to seep into the combustion, but I doubt it in your case. There's no harm driving with the sensors like that.

81corolla

Ok, neg. battery disconnected. I'll leave it overnight. Radio stations lost is ok.

Bad gas - I'll use 91 next time.

Bad air - that's interesting. Ohio experienced a warmup this weekend, in the 60's (which is why I worked on the car :-) but now it's back down in the 30s. Perhaps the rapid air change...

Well, I've noticed what seems to be just the opposite. When I take my foot off the accelerator, the car slows down a little due to engine compression. That is to be expected especially with a V6.

But it "seems" like the "lag" is just a little too much. I thought the ATF change would make coasting a little smoother, but I didn't see much improvement there (shifting is great though.) I'm probably over analyzing it.

Anyway, I'm a German Castrol 0W-30 synthetic user and am just at my 5000 miles change. I checked the dipstick and it's right at half way, so I may be burning a little oil, but nothing like shot piston rings.

I'll let you know how things are tomorrow. Thanks.

Lexmex

There is something I am planning to buy this weekend, an oil additive, to help reseal my piston rings, http://store.interautopartssd.com/mo...aver-p-24.html

Some of the guys at my track swear by this stuff, so given that I don't use an air filter (at least until this weekend, you'll see), I will give it a go.

There is a little place on the highway nearby where I got my gear oil and they have this.

81corolla

Sorry I didn't follow up on this sooner - things got busy...

Last week, I disconnected the battery overnight. Drove about 100 miles before CEL came back on. Took it to Advance Auto and had the codes read again.

Same ones: P1130 and P1150. Although the P1130 showed "Pending" whatever that means.

I had also cleaned the MAF for good measure but didn't help.

I still have to put a fresh tank of 92 octane gas in it. The problem might just be bad gas. Let's hope.

Based on the other threads, it appears somewhat "normal" for the A/F to go bad and 83K isn't premature. But before I sink $300 into parts alone, any other ideas?

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P1150 is bank 2 sensor 1 and P1130 is bank 1 sensor 1.
Looks like these A/F are on the exhaust manifold (front and back).

http://www.autoshop101.com/forms/h37.pdf

The front I might be able to get to easily. The back looks harder. Any threads on this job?

The sensor is threaded into the manifold but how does the wire disconnect from the other end of sensor? Is it threaded, clamped on, etc?

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The Toyota and Lexus A/F sensor is part #89467-48011. The Denso sensor is part #234-9009. Are they the same?

This thread:

https://www.clublexus.com/forums/sho...d.php?t=339472

pointed to this store for $150 A/F sensor for the ES300:

http://www.factorylexusparts.com/ser...IR-FUEL/Detail

Thanks for the help.

Lexmex

Is the P1130 by itself or does it just show pending?

81corolla

The meter showed three codes; I believe in this order:

1. P1130
2. P1150
3. P1130 - pending

I will double check next time. Still going to add fresh gas and reset.

Lexmex

I would also try some fuel injector cleaner. The stuff from Restore works well, though I like the Redline Fuel System Cleaner (can get it at AutoZone). Sometimes if bad gas or crud goes through, it can get on those sensors and create a mess. Happens here a lot to people.

TampRX300

Ordered my A/F sensor today. $152 shipped, Denso.

81corolla

Might I ask from where?

TampRX300

as Optimus Prime said.... "Ebay"