Check Engine Light
#1
Lead Lap
Thread Starter
Check Engine Light
I had a check engine light thread in 2013 which turned out to be Bank 2 Sensor 1 . I just noticed my check engine light on with the word check. Once again, car is running fine and trans shifts fine. Gas cap is on tight. Only symptom I could mention is that my car has been slightly pinging under hard acceleration for quite some time...even years. I use 93 octane Chevron most of the time. Yes, I need the code/codes but prefer to take to my Indy rather than Autozone. My 2001 LS430 has 132,000 miles. Any clues? No smells and my gas mileage with 99% city driving has always been crappy since the day I purchased the car 8 years ago. I'm hoping for another 02 sensor, but would cringe if it's a catalytic converter. The car runs perfectly with plenty of power and no noticeable smells or symptoms. Any clues? PS...If the light is off tomorrow morning, will it be stored so that it can be pulled up?
Last edited by Bocatrip; 11-21-17 at 01:13 PM.
#3
Without the codes, any
My 2¢...
#4
Lead Lap
Thread Starter
My Indy came up withe 2 codes. P0171 and P0172. Bank one lean and Bank two lean. He suspects but can't be certain it might be the MAF sensor. He blew it out with compressed air and reset the CEL. He needed more time to diagnose thoroughly before suggesting I replace the MAF sensor. Anyone out there with any feedback or suggestions? My car is a 2001 with 133,000 miles. Many years ago I did replace Bank 2 Oxygen sensor 1. Car runs fine when the light was on. Hasn't come back on, but I only drove approximately 15 miles since resetting. Any feedback would be greatly appreciated. Thanks all.
#5
Strange that it's both P0171 (Bank 1 too lean) and P0172(Bank 1 too rich). I'd check the Y-pipe for an exhaust leak and if that isn't it I'd probably just replace the O2 sensor...
#6
Lead Lap
Thread Starter
#7
Moderator
I'd call around and find a parts store that allows reasonable returns on parts and go buy a new MAF and install it right there in the parking lot (takes 5 minutes if you take your time). Some stores including Lexus dealer usually will allow you to try it out on your car since the install has no effect on the new MAF and return if it same day if it does not solve the issue. It may cure the problem and if it does not cure the problem swap your old MAF back in and return the MAF.
Trending Topics
#8
Lead Lap
Thread Starter
I'd call around and find a parts store that allows reasonable returns on parts and go buy a new MAF and install it right there in the parking lot (takes 5 minutes if you take your time). Some stores including Lexus dealer usually will allow you to try it out on your car since the install has no effect on the new MAF and return if it same day if it does not solve the issue. It may cure the problem and if it does not cure the problem swap your old MAF back in and return the MAF.
#9
Lexus Champion
I had a check engine light thread in 2013 which turned out to be Bank 2 Sensor 1 . I just noticed my check engine light on with the word check. Once again, car is running fine and trans shifts fine. Gas cap is on tight. Only symptom I could mention is that my car has been slightly pinging under hard acceleration for quite some time...even years. I use 93 octane Chevron most of the time. Yes, I need the code/codes but prefer to take to my Indy rather than Autozone. My 2001 LS430 has 132,000 miles. Any clues? No smells and my gas mileage with 99% city driving has always been crappy since the day I purchased the car 8 years ago. I'm hoping for another 02 sensor, but would cringe if it's a catalytic converter. The car runs perfectly with plenty of power and no noticeable smells or symptoms. Any clues? PS...If the light is off tomorrow morning, will it be stored so that it can be pulled up?
Also; Replace all.O2 sensors
#10
Lead Lap
Thread Starter
Replaced one 02 sensor a few years ago which was an OEM part. My Indy cleaned the MAF with forced air today. He mentioned cleaning with a spray might harm the MAF and didn't go there. Replacing the other 3 with OEM can be a very expensive proposition instead of replacing the MAF. I'm also considering going to Lexus for the $99 diagnostic and see where it goes. With Lexus they back it up 100% in case a wrong diagnosis. I could also go elsewhere with the Lexus Diagnosis if cost is too high. In the mean time, the car is performing fine, light is still off. I have time to decide. Decisions decisons! lol
#12
Lead Lap
Thread Starter
Thanks. I'm just hoping that my Indy is interpreting things correctly.. If not.. I'm going in the wrong direction.
#13
Lead Lap
Thread Starter
P0171 and P0172 were supposed to be that Bank 1 and 2 were both too lean. Is this incorrect?
#14
I'd call around and find a parts store that allows reasonable returns on parts and go buy a new MAF and install it right there in the parking lot (takes 5 minutes if you take your time). Some stores including Lexus dealer usually will allow you to try it out on your car since the install has no effect on the new MAF and return if it same day if it does not solve the issue. It may cure the problem and if it does not cure the problem swap your old MAF back in and return the MAF.
Second, depending on how one drives, this problem might take several days to reappear after the OBD system has been reset. So you might think that you've fixed the problem only to have it show up later...
#15
You don't know this. This is the type of problem that generally takes time to trigger the OBD system. It is also the type of problem that can/will damage your catalytic converter. Find out what kind of diagnostic equipment and capability your Indy has or take it to the dealer to get it repaired...