Air Flow Sensor
05-31-06, 03:05 PM
#1
Driver School Candidate
Thread Starter
Join Date: May 2006
Location: IL
Posts: 1
Likes: 0
Received 0 Likes
on
0 Posts
Air Flow Sensor
I have '01 RX300 4and have had engine light come on and off for some time now. It was off for 4-5 moths last summer until it started lighting up again this winter.
Finally, I recieved two codes from the mechanic today PO1130 and PO1150 which according to Lexus code retrieval points to O2 sensors in both banks. Also, mechanic said that it stated Lean Bank 1&2 following the diagnostic run. Does this sound like problem with O2 sensors or Air Flow sensor since it appears to be affecting both banks.? They did say that the Air Mass Flow sensor was dirty and cleaned per my request since they were not sure what to replace. I figured driving with cleaned sensor for few weeks should be enough to determine if I should replace it or if cleaning fixed the problem. Another thing I noticed is that engine T runs on low side (does not reach second line) for most of the time, but this weekend during warmer weather and 500 mile trip without light on, engine T was in the middle of the range as one would expect. Does anyone have relevant experience with this?
Finally, I recieved two codes from the mechanic today PO1130 and PO1150 which according to Lexus code retrieval points to O2 sensors in both banks. Also, mechanic said that it stated Lean Bank 1&2 following the diagnostic run. Does this sound like problem with O2 sensors or Air Flow sensor since it appears to be affecting both banks.? They did say that the Air Mass Flow sensor was dirty and cleaned per my request since they were not sure what to replace. I figured driving with cleaned sensor for few weeks should be enough to determine if I should replace it or if cleaning fixed the problem. Another thing I noticed is that engine T runs on low side (does not reach second line) for most of the time, but this weekend during warmer weather and 500 mile trip without light on, engine T was in the middle of the range as one would expect. Does anyone have relevant experience with this?
05-31-06, 04:31 PM
#2
Super Moderator
Let's take a look at these error codes:
P1130 & P1150 are both listed as A/F Sensor Circuit Range/Performance Malfunction
Difference:
P1130 refers to Bank 1 sensor 1 and P1150 refers to Bank 2 Sensor 1, so those would be the two O2 sensors immediately before the precats ony your exhaust manifold.
It could be the O2 sensors themselves, the circuit (wires, connection included) or the ECM (doubtful).
The RPM can differ depending on the air going in (both the temperature and velocity) as that is the function of the MAF sensor (different from the O2 sensors on the exhaust) but they work together. In this case on your trip, the velocity of air going in was higher, but when you were at idle or low speed there would be an issue there with the RPM being low.
The MAF sensor cleaned is okay (and that would ordinarily throw a P0171 error), but also take a look at your air filter to see if that is clean or needs replacing.
As we mention on this forum, merely putting back in a clean MAF sensor is not enough without pulling the EFI fuse in the fusebox for a few seconds (after the vehicle is turned off and the key out of the ignition) to clean out any of the recorded information in the ECM that originally triggered the check engine light. Then drive a mix of highway and street driving for about an hour and see if the light shows up then (probably takes longer). If both codes come up again, I would then think the O2 sensors need replacing, not the MAF (otherwise the P0171 error should also come up). I know some bad gas down here can screw up O2 sensors (thankfully Toyota/Lexus quality is good compared to the rest of the industry).
P1130 & P1150 are both listed as A/F Sensor Circuit Range/Performance Malfunction
Difference:
P1130 refers to Bank 1 sensor 1 and P1150 refers to Bank 2 Sensor 1, so those would be the two O2 sensors immediately before the precats ony your exhaust manifold.
It could be the O2 sensors themselves, the circuit (wires, connection included) or the ECM (doubtful).
The RPM can differ depending on the air going in (both the temperature and velocity) as that is the function of the MAF sensor (different from the O2 sensors on the exhaust) but they work together. In this case on your trip, the velocity of air going in was higher, but when you were at idle or low speed there would be an issue there with the RPM being low.
The MAF sensor cleaned is okay (and that would ordinarily throw a P0171 error), but also take a look at your air filter to see if that is clean or needs replacing.
As we mention on this forum, merely putting back in a clean MAF sensor is not enough without pulling the EFI fuse in the fusebox for a few seconds (after the vehicle is turned off and the key out of the ignition) to clean out any of the recorded information in the ECM that originally triggered the check engine light. Then drive a mix of highway and street driving for about an hour and see if the light shows up then (probably takes longer). If both codes come up again, I would then think the O2 sensors need replacing, not the MAF (otherwise the P0171 error should also come up). I know some bad gas down here can screw up O2 sensors (thankfully Toyota/Lexus quality is good compared to the rest of the industry).
Thread
Thread Starter
Forum
Replies
Last Post
