When you click on links to various merchants on this site and make a purchase, this can result in this site earning a commission. Affiliate programs and affiliations include, but are not limited to, the eBay Partner Network.
Hey guys, looking for some help here... When I bought my ISF it had codes P0157/P0156 and P0137/P0136 stored in the system (downstream sensor 2 malfunction on both banks). When I bought it I started diagnosing a little. I noticed one of my A/F sensors had an O2 sensor in place of it for some reason so I replaced both with OEM A/F sensors. I also tried spacers on both downstream sensors with no luck. Recently I replace both downstreams with OEM Denso's and still no luck. My only thought left is there could be a leak somewhere or an issue with my ECM.
Worth noting I have sikky headers and no cats at all. Wondering if any of you have ran into an issue like this. Any info would be greatly appreciated! Thanks
Open the ECU box to see if an O2 simulator is installed. I had this same issue. There was one poorly wired in. They don’t work great regardless. If there is one… Get rid of it, order some PPE O2 simulator extensions. They are L shaped spacers that go in the exhaust. Clear the codes and enjoy.
Thanks for the reply! I did have a look a while ago and I did not have any simulators wired in, That was my first thought also. Can I purchase the spacers straight from PPE' website?
Just to share, when I installed my PPE headers, I had a P0420 and P0430 CEL popped. The path I took was to install the RR Tune since it coded the P420/430 out.
mine has thrown that a couple times since you posted. It seems to be more related to wiring than the lack of cats. My car used to throw this code more when I had an O2 eliminator kit in it, poorly installed by the previous owner. I thought I had solved this problem for good.
mine has thrown that a couple times since you posted. It seems to be more related to wiring than the lack of cats. My car used to throw this code more when I had an O2 eliminator kit in it, poorly installed by the previous owner. I thought I had solved this problem for good.
Were you able to resolve this issue? I just started having this code (P0157 only) pop up after years with no issues. I have changed both downstream O2 sensors, and checked for any exhaust leaks, but the problem won't go away and the code keeps popping up.
Were you able to resolve this issue? I just started having this code (P0157 only) pop up after years with no issues. I have changed both downstream O2 sensors, and checked for any exhaust leaks, but the problem won't go away and the code keeps popping up.
No I parked it and have been remodeling a home. However, I have a plan.
1. First is new sensors.
2. Make sure they are installed with zero twists in the wiring, per JoeZ’s instruction.
3. Remove one of the little restricters in the PPE simulators (L elbows).
No I parked it and have been remodeling a home. However, I have a plan.
1. First is new sensors.
2. Make sure they are installed with zero twists in the wiring, per JoeZ’s instruction.
3. Remove one of the little restricters in the PPE simulators (L elbows).
What headers do you have?
I have PPE headers. The car had the O2 simulators from the previous owner. Hoping that this was causing the issue, I removed them because I have the RR Racing tune. Then I installed the new O2 sensors, but no luck. Going to take another look at the wiring to the sensors tomorrow, but other than that, I'm running out of ideas.
See post 27 onward in this thread. JoeZ gave some great tips. I plan to try them all.
Mine ran fine for a while too. The CEL came on when the weather started to fluctuate. I’m wondering if that could possibly be related, but it’s speculation at this point. These cars are more sensitive to the O2 sensors then other platforms I’ve had. It can be frustrating.
I thought I saw someone else here on CL that about this same problem.
What it ended up being was the wire extenders used to extent the O2 sensors further for the PPE Headers. Do you have extension connected in the factory plug in end to extend to the sensor to reach the PPE Header bung?
I believe those are used on the primaries. The secondaries don't generally get them. I know mine don’t have them. I’m following the same member’s issues. I will be removing my extensions on the primaries, If they are in fact there. But the code in question relates only to the right passenger side secondary.
See post 27 onward in this thread. JoeZ gave some great tips. I plan to try them all.
Mine ran fine for a while too. The CEL came on when the weather started to fluctuate. I’m wondering if that could possibly be related, but it’s speculation at this point. These cars are more sensitive to the O2 sensors then other platforms I’ve had. It can be frustrating.
Thanks for the link, this is helpful.
I had the electrical simulator in the ECU. When I first started having this problem, I read other members who had these simulators and the RR Racing tune have problems with the CEL. Once they removed the O2 sim, the CEL went away, so I tried it, but the CEL came back.
This issue started after I took my car to the dealership for service. I start my car, and the first thing I see is the CEL, so I go back to the service advisor and tell him. He then tried to tell me the car was running lean because there wasn't much fuel in the tank, so they just cleared the code and sent me on my way. I'm trying to figure out if something they did during service damaged something connected to this O2 sensor.
I believe those are used on the primaries. The secondaries don't generally get them. I know mine don’t have them. I’m following the same member’s issues. I will be removing my extensions on the primaries, If they are in fact there. But the code in question relates only to the right passenger side secondary.
Ok got it, I missed that part and without looking it up, I get mixed up on the Bank ? Sensor ? codes?
With that....... I would think on a normal path a few things.
1. The wiring/connectors somewhere is bad? Those thing sense like mil amp/votls +/- or something real sensitive that it has to read the range not to code. So my tjought would be wires, connector, ether end of the Sensor wire being that you put in new correct sensors already. Or you are 100% sure you have the correct type sensor you used to replace with?
2. The Tune - maybe for your car, fuel, climate, air the car is actually coding due to a too lean condition? Do you know if the car had a Tune loaded?
My car originally had a P0159 when I bought it (unbeknownst to me, randomly came on), indicating a delayed signal. We traced that back to a bad wiring job on a CEL eliminator. During that process, I went in to autozone and ordered an oem O2 sensor and installed it. I thought it was odd that it didn’t have a little heat shield on it.
Every thousand miles are so, I’d get a P0157, which means the voltage was low. Then it started happening all the time. I parked my car due to a remodel and busy life.
I finally addressed this today. It doesn’t look like I had the correct sensor. I can’t tell what unit it is via internet searches. But the Denso unit looks different and says Denso right on the side.
So my P0157 fun continues today. I made it about 200 miles. So far I’ve replaced the sensor, made sure there were no twists in the wires, and replaced the header to mid pipe gasket. Any ideas what else the issue could be? This has been a bit of a frustration.
Cel help!
