Tjfaz

Ok so about a month ago my check engine light came on with the engine symbol and traction control off symbol. I took it to Autozone and the car in one shot apparantly threw four codes. The codes are P0125, P1135, P1150, P1155. Now at auto zone they told me both Upstream o2 Sensors and MAF sensor are bad Via the OBD when the plugged it into the car. The only physical symtoms of anything being wrong with the car is at around 1500 Rpm's the car studderes if you want to call it and I can feel it in the gas pedal then drops below 1000 Rpms then revs back up again once I press down on the accelerator. Now to get just the 02 sensors fixed its like 600 bucks and if I can get the problem narrowed down I could do it myself. Thanks so much I apprecite if I can get some sort of input. -Semper Fi LCpl Fazio

MrShim78

you should do the following in my opinion

1. a code reader and software is between 30 and 50 bucks on ebay. get one, or go somewhere else and confirm the codes.
2. o2 sensors are cheaper than most think, check on rockauto.com and there are plenty of articles here on o2 sensors and hw to replace if you want to DIY
3.if the MAF IS bad thats bad news, but you can prob get a cheaper one at a salvage yard. these last a long time usually not sure how yours is bad?
4. look at lexus obd trouble codes , for example, here : http://www.obd-codes.com/trouble_codes/lexus/ and decide what will probably fix the issue.

again o2 sensors , some are a pain, some are easy. you can probably DIY most of them. and the maf, its a really easy replacement. 600 bucks is rather insane if you ask me. the MAF is expensive, but 02 sensors i think are under/around 50 each? you can get done in under 200 if you DIY?

MrShim78

one more sign that your o2 sensors are bad is that fuel consumption gets really bad and the engine runs rich.
o2 and MAF regulate the fuel/air mixture so they are important, dont ignore the issue but i dont think it will cost 600 to fix!

Tjfaz

Thanks guys I was really just trying to see if anyone had similar problems and narrow down the problems because there are so many different codes. Thanks for the advice!

hzt30

(P1135, P1155) Your heater circuit on bank 1, sensor 1 is bad. This can easily be check with an ohm meter. This sensor is an A/F sensor and not an o2 sensor.

Your MAF sensor may not be bad but just dirty. They can be cleaned with MAF sensor cleaner.

You need a scanner to read data stream and you can check the operation of all sensors, check freeze frame data, fuel trim, etc. You can clear codes and see which codes come back.

Some of these codes may be related and it might not be as bad as you think.

Tjfaz

Update, Went to Auto Zone today and cleaned the MAF. The check engine light did not go off but the guy at Auto zone cleared all the codes. The Check engine light has not come back on when it usually does the second I pull out of Auto Zone. The car still has an idle problem and especially when I take off from a dead stop in the 1000, to 2000 rpms. Anybody have any idea?

Tjfaz

Bump Need advice!

moonphase

Flat spots in acceleration and rough idle usually indicate a defective throttle position sensor (located on the rear side of the throttle body), dirty MAF sensor, dirty intake/ throttle body, and dirty IAC valve. A new TPS can be acquired on ebay for around 30.00, find a Denso TPS for your vehicle. Intake can be cleaned by hand from the throttle body side, and also the ACIS end by removing the plate on the passenger side.

Tjfaz

Update. Cleaned the MAF and installed new TPS. Both the Trac Off and CEL is on again about 10 mins after the battery was reconnected. As of now the car idles in between 600 RPM's and 1200 RPM's. The car shakes and when accelerating, seems to be a bit laggy and jerky. I think my next step is to change out the upstream 02 Sensor between the engine and firewall. Any suggestions....

moonphase

Multiple codes at the same time doesn't mean that every one of those components with a code are defective. Each code is saying that the reading is out of specification, and just giving clues that will lead to the defective component (s) through proper interpretation of the symptoms. Diagnosing computer controlled cars is not straight forward as is with older cars, as the PCM constantly adjusts the Fuel trim as components deteriorate, and leading to other components seeing problems in specification.
You might need to go to a qualified mechanic for code interpretation!

moonphase

An example of interpretation follows:
Our 2006 Ford Fusion had a check engine light on so we went to the Auto Zone and had the code read. The code was for (engine temperature sensor out of specification), so the sales person, who had been a Ford mechanic for a few years, stated: The temperature sensor is bad!" I took his advice,spent a couple hours replacing, a new OEM $50.00 temp sensor, cleared the code, and thought the issue was fixed. The code came back the next day. so I spent a week on the internet reading different forums and came to the conclusion that the temp sensor was just doing what it was supposed to, and the thermostat was sticking open. This caused the engine to take longer to warm up than should have, so the PCM set the code for sensor reading out of specification. Another $50.00 and 3 hours replacement time later, the car was finally fixed. No more codes!

tomf

I'm no expert but these cars are notorious for the MAF and the O2 sensors going bad. Based on my experiences, first I would clean the MAF (you've already done that), second I'd look for any obvious vacuum leaks, Third I would replace the Bank 1 Sensor 1 O2 sensor. Fourth replace the MAF. In the worst case you'd just be replacing a sensor that you would need to replace anyway. In the best case it would fix your problem.


BTW if you are mechanically inclined you can replace the MAF and O2 sensor yourself. A refurbished MAF is about $80 and an new O2 sensor is about $110.

I own 3 cars with the 1mz-fe engine. On all of them I've had to replace the Bank 1 Sensor 1 O2 sensor. One at 105K miles, one at 135K miles and the other one at 175K miles. I've never had to replace the MAF. I did replace it one time because the advice I got was the MAF was more likely the cause then the O2 sensor. In my case it turned out the O2 sensor was bad. Based on my experiences I'm more likely to believe the cause is the O2 sensor. I also recommend that you use a Denso O2 sensor. Denso is the OEM manufacturer of the O2 sensor for Lexus.

Tjfaz

Update: Car idles like crazy, car shakes and just now the RPM's dropped so low it stalled. In the mail I have bank 1 Sensor 1 and bank 1 sensor 2. Even though I cleaned the MAF, maybe it is completely broken and can't be cleaned.

yeskay

tomf:
did you get specific code when you replaced the b1s1 o2 sensor. thanks.

Tjfaz

Hey man the code is P1135