hblex

I came back from vacation and my battery was dead. A few jumps and not much progress led me to Sears to have it replaced. On my way home, the check engine light came on. I looked under the hood and found I needed coolant – which I added. The light went out for about a week. When the light came back on, I took the car back to Sears thinking that maybe they knocked something lose. They did a read on the car, the codes P1130 and P1135 (manufacture controlled fuel and air metering) came up. Sears cleared the codes. The check engine light was off about 1 minute and came back on.

From looking at comments on this web site – I noticed that maybe with luck that if I pull a fuse I might reset the panel. Or, the more likely solution, is that I may need a mass flow intake meter. If this is the case, do you think it is strange that I had it replaced in July of 2005? A Lexus dealer fixed it – do you think they will honor their work?

Any advice would be helpful – Maybe I walking down the wrong line – and it could be something else. Any advice would be helpful.

Lexmex

Well, you obviously did some searching on CL.

These errors are more related to the O2 sensors located on each exhaust manifold. I am attaching a picture of one you can see in your engine bay (Bank 2, Sensor 1).

O2 sensors are not cheap nor to install (with professional help).

What you should first do is pull out that EFI fuse and pull both battery cables off. After at least 15 minutes (I mentioned this in another email today), put the fuse back in and reattach the cables. Then, in this case, watch over the next few days to see if the light comes back on. Usually, I prefer a 50/50 city/highway 1 hour drive, but gas ain't cheap.

Another thing, I would want to know, what is your Idle RPM when you have the vehicle in D and pressing on the brakes (as when stopping at a stop light)?

This might also give me and the rest of the CL members if there could be a chance of an IACV or fuel injection that could be affecting the O2 sensor readings (O2 sensor could be working fine, but getting funny readings that could throw a CEL).

The last step (and hopefully you don't have to take it) is to get your hands on or get to a mechanic (need not be Lexus or Toyota), that has an OBDII scanner than can check the O2 sensors. Some are really fancy and they show a little graph that can tell if the O2 sensors are ticking or not. It's a lot cheaper than playing hit and miss, especially since there are two possible sensors that are the culprits.

A comment about the MAF sensor. I don't run an air filter. In fact, last time I remember an air filter being on my RX300, Bush was still worrying about re-election. Yes, they can fail and they can get dirty. You can easily take the MAF sensor off (two screws) and see if the red diode is dirty or not (and it can be cleaned quite easily if it is).

toy4two

I would clean the MAF sensor with some alcohol and compressed air first. 10 minute job. The Lexus parts warranty is only 1 year, so you are SOL from them. I once "cleaned" the MAF on a Ford ranger and used a little too much pressure and broke the hot wire, so be VERY CAREFUL.

But the o2 sensor is a consumable, and at high milage may need replacement. They aren't cheap and you'll see many people get that error code at some point. Stupid EPA! LOL.

hblex

I pulled the fuse (but not the battery) and the engine light went out for 10 miles. It is back on. The car is running a between 750-1250 rpm when idling. Is that normal?

hblex

lexmex - I forgot to mention that I did not see your attachment showing where the O2 sensors are. I am new to this so maybe I am not looking in the right spot. Thank you.

Lexmex

My bad, this was the one I was referring to.

Lexmex

This is the other one, Bank 1, sensor 1 behind the engine block.

Lexmex

I would still pull the battery as I mentioned. Were you able to check the MAF sensor?

Normal engine RPM is 750, but can go up and down depending on issues like air temperature.

As I mentioned earlier, there are only a few other things such an IACV valve need cleaning or even some clogging in the fuel injectors as that could affect some readings.

The absolute real way to know is what I mentioned earlier, and it should not cost too much. I know Toyota down here can check it for $25 USD roughly as an example (I have no idea in the states how much they are running), and I am referring to the O2 sensors shown in the previous pictures. They can stick a very advanced OBDII scanner into your vehicle an examine the readings coming from these 2 O2 sensors. I am pretty sure some independents have them. Thre really is not much of another way to know what is going on with the O2 sensors short of replacing them.

Lexmex

Just as a reminder to everyone, with regard to those P1130 and P1135 codes, there are 3 possibilities:

1. ECM (not likely, other issues, too)
2. The A/F or O2 sensor (I am going to start using these interchangeably again, as down here, they are, too).
3. A/F sensor Trip detection (a.k.a. something went bump in the night or that sensors themselves detected a certain condition but the sensors themselves may not be screwed up)...this is what we have been trying to rule out by examining the MAF sensor, fuel injection, IACV valve, etc. and of course disconnecting the battery and EFI fuse.

RX300Gary

P1135 is Heater circuit for the Bank 1 Sensor 1 A/F (air fuel ratio) (ox sensor).

Ox sensors do go bad, this is likely the problem. The heater is a a 12V hot
wire that gets it warm when you turn the engine on and before the exhaust
flow has time to warm it by itself. During this engine startup time, because
the heater is bad, the engine will not be running at the right A/F mixture,
causing P1130 to get set.

It could be a wiring problem (unlikely) so measure for 12V at the sensor plug.
Our RX300 only has 70K and hasn't needed a new sensor yet so I don't know
how long they last but they ARE a replacement item after some number of
miles.

They usually have a plug and they just unscrew like a sparkplug, shouldn't
be any big deal to replace (except Bank 1 is accessible from underneath,
right Lexmex??)

If it runs ok, you can probably drive it but you may be endangering your Cat
converter.

Gary

Lexmex

That's right Gary with regard to Bank 1. Either you have to get it up on a lift, jack it up just right, or have something like my uncle has, an open area of concrete normally covered by a steel plate.

The danger you describe can indeed exist. I don't know about Lexus from any specific experience, but my uncle has worked on a few vehicles (earlier 90 Fords and Chevys) with a bad sensors where excess fuel went past the combustion mixture and screwed the cat. MEEEOOOOW!

toy4two

here is a tip for o2 sensors, soak the o2 sensor hole with a quality penetrating oil like PB Blaster, (not some WD40 crap), then come back to remove it in a few hours. Those things can be very difficult to remove without doing this.

RX300Gary

I got my scan gauge today. Guess what? I had codes P1135 and P1155.
Very interesting. There are some bad sites on the web for these two codes,
P1135 seems to be REALLY popular. It is the Bank1 Sensor 1 as previously
stated. But I also had P1155 which is the A/F (ox sensor) heater on Bank2
sensor 1. Both my heaters looked bad. Consulting the wiring diagram, I saw
there is a 25A fuse AND a relay for the heater circuit. I pulled both and
checked them and they were FINE. So I disconnected the bank2 ox sensor
and its heater measured the exact 1.2ohms I found on another thread for the
Toyota sensor (BTW, that thread said the Denso sensor is 8ohms and will not
turn the lights off.. however, mine IS a Denso from the factory!!)..
I measured the plug from the ECU, about 9.8V which sounds about right. I put
it back together, reset the codes for the second time and now the lights are
staying off!! I FIXED IT.. or it fixed itself..

So hblex, try getting the codes reset a couple times and see if that doesn't
fix it... BTW, I tried pulling the fuse and disconnecting the battery, had my
wife driving it all week and none of those fixed the lights..
Gary