Check engine light and code P0135

Hi,

There is a fuse. It is A7 (15amp) in the underhood fuse box. For some reason, my manual doesn't have a layout of the fuses. See pic 1. That is what I have.

Now, start by checking that fuse. In addition to inspecting the fuse, confirm there is power both to it and from it. Here is a link to help:

https://www.2carpros.com/articles/how-to-check-a-car-fuse

Let's start with that. Let me know what you find or if you have other questions.

Take care and God Bless,

Joe

Thanks you so much! I will definitely check that fuse today and update ASAP!

You are very welcome. Let me know what you find or if you have other questions.

Joe

Hello Joe, i just checked the fuses i replaced it with a new one but it was good from the start. I checked them both and none of them seem faulty on a multimeter. I tested the brand new O2 sensor and when i touched the leads to the what i think is the heater unit(the two same color black wires) it dropped to 0.00 it didn't say open lead. The multimeter was set to 200 ohms. I still have the code show up on the scanner this is the first time I clear it with the car in on position as opposed to actually cranked and motor going. But I’m not sure which step to take next. The check engine light still hasn’t came back on nor the permanent code in the scanner just the confirmed code.

Another update, on the wiring harness that connects to the O2 sensor, i checked the leads of the same thing the two similar colored wires in this case they’re both red, and i checked their resistance and I believe they are reading open. Multimeter set at 200 ohms instead of reading any type of number like 0.00 the multimeter just read 1. And when I switched to voltage just in case it was user error on my part using the wrong units, it stayed at 1. Then when I tried to put the car in the on position same reading.

Edit: i tried to do it again with more purchase on the leads for each side and it started climbing to 200 and once it got to 200 i guess cause i was on 200 ohms it just went to 1. When i switched to 200k it got a small reading of about 0.01-0.03.

If you are getting an open at the sensor, it sounds bad. Is this one that you replaced?

Joe

It is the one I replaced. I checked it again at 200k ohms and it got a reading. I also have an update, after clearing the code with the car in the open position after driving the car around and scanning the car again it now reads zero codes. I’m not sure if that’s all it needed or if something else fixed it like the switching of the fuse and it took awhile to register? I’m not going to lie I’m a little confused.

Hi,

It could have been a connection issue due to corrosion or anything. And yes, removing and replacing the fuse could have allowed for a better connection.

Let's hope it doesn't come back on. If it does, let me know.

Take care,
Joe

Thank you I really appreciate it and value all your help!

Thank you, take care, and God bless!

You are very welcome. If something changes, let me know. Also, feel free to come back anytime in the future. You're always welcome here.

Joe

Thank you so much! I really appreciate it!

Have you made any progress? If you can, let me know. I'm interested in knowing.

Joe

Hello,

Yes, I’ve kept scanning it and no code has returned. I’ve also pressed the smog check option on my scanner to check if it were to pass a smog check and it says yes as no codes found. That’s of course not including the other tests that would be run during a smog check.

Hi,

I'm glad to hear it is working properly. Thanks for letting me know. As far as the scan tool, I believe what you are referring to is the emission's readiness selection. That indicated all modules have been reset and passed. That's a good thing.

Let me know if you have other questions or need anything.

Take care and again, thanks for getting back to me.

Joe

Hello Joe, I have another update on the Honda. After having driven it for a couple of days and even drove it 72 miles miles yesterday, I decided to take it to get its smog check. Unfortunately, it did not pass. There is not light, my scanner doesn’t read any codes, and the car is running great still! But it did not pass because the evap system and the O2 sensor are “Not Ready”. The technician only spoke to me about the O2 sensor telling me that the car still needs to be driven around more and that I shouldn’t take it above 60 MPH. That I have 30 days from today’s date to take my car back for a retest. What I’m confused about is I’ve tested my car with my obd2 everyday since and I’ve received no codes and not check engine light ever came back so I have no idea what to do.

Hi,

The different modules need to complete a drive cycle which is variable. It sounds like two of them were incomplete. Does your scanner have an emissions readiness setting? That will tell you if all the modules have completed.

Let me know.

Joe

It does and every time I did it, it said that it was good to go the only thing it said was “catalyst has not yet completed this test, Evaporative system has not yet completed this test, oxygen sensor has not yet completed this test” but I thought that just meant I couldn’t be run with just a scanner. Everything else came out good. The smog check place only said the evaporative system and oxygen sensor on their report, and the technician only told me about the oxygen sensor when speaking to me and told me to drive around for a few days.

Hi,

That is exactly what needs to be done. I'm not sure where you are located, but I'm in PA. Here, we are allowed to have one incomplete and it will still pass. More than one, we can't inspect it.

Keep an eye on it. Once you see everything is complete, take it in for inspection.

Let me know what happens or if you have other questions.

Take care,
Joe

How do I do the drive cycle? Is there any specific steps I take? I heard here in CA they allow the evap system as the only exception, I’m assuming maybe that’s why the technician only spoke to me about the O2 sensor?

Thank you so much!

Hi,

It would be really odd for them to not include the EVAP. That is what prevents gas vapors from entering the atmosphere.

As far as a drive cycle, there is no specific step for any of the systems. All you can do is keep driving it until it decides to complete.

I wish I had an easier answer, but I don't. Some reset very quickly and others seem to take forever. I've already put 200 miles on a customer's car to get it ready for the emissions inspection. I miss the old days. LOL

Take care and let me know if I can help and how things turn out for you.

Joe

Thank you so much! I really do appreciate it! I’ll continue to drive it and monitor it. I really cannot thank you enough for your help.

It was much easier before eh? Hahaha

Thank you again! I’ll keep you updated! Take care and stay safe.

You are very welcome. I will watch for your reply.

Joe

Hello Joe,

I found a “steps to take” style webpage yesterday and decided to try it. It told me about how exactly to run the car from turn on to turn off and between the drive to complete a drive cycle for my Honda. After the drive I decided to check if all the sensors were ready by using the check engine light in the on position I had found a video saying that if you put the car into the on position and after 20 seconds, if the check engine light turns off completely all sensors are ready, if a sensor isn’t ready after 20 seconds the check engine light will flash 5 times then turn off. Yesterday it flashed 5 times confirming not ready. Today it didn’t flash after 20 seconds it went completely off. After that I plugged in my obd2 scanner to double check this time, and the scanner confirmed everything was green and ready to go. Should I take it in to get re-smogged tomorrow? And also should run my scanner again prior to the test to make sure?

Hi,

If the light is off and everything is reset, get it checked as soon as possible. You shouldn't have to scan it again unless the check engine light turns back on. Don't disconnect the battery or clear any codes. You'll have to start over again. LOL

Let me know.

Joe

Hello Joe! Great news my car has now passed smog, runs great, and all I’m doing now is waiting for my new registration to arrive! Thank you so much! I really appreciate your help! It really helped so much and thanks to your advice my car is working well and passed all it’s tests! Thank you!

Hi,

That's great news. I'm glad to hear it. Please feel free to come back anytime in the future if you have questions. You are always welcome here.

Take care,

Joe

Thank you much appreciated!!!! Will definitely come back if I need any help or have any questions. Stay safe and Take care!

Hello Joe! Hope you’ve been well. I have a concerning check engine light that popped back up. I had received a P0420 code before my previous P0135 code. When I had taken my car to get fixed for the catalytic converter it fixed the P0420 code it was no longer in the permanent codes. Then after I had received the P0135 code. After that's when I fixed the O2 sensor problem as I thought that was something I could do since it's nothing big. Now after the car had received a new catalytic converter now it flashed the P0420 code again. And it has only been in there for about a month or two. What's worrying me is that the cat was good, I passed smog and had no lights last time I posted on here, so what is causing this? I don’t to have to keep taking my car in for fixes especially not if I have to take it into Honda where they charge an arm and a leg.

Hi,

That is odd. Do you know if the new converter is an OEM converter? Also, all "new" converters carry an extended warranty, so if it is bad again, it should be covered under warranty.

Is the P0420 the only code? Also, you said the light was flashing. If that is the case, that is usually an indicator of a cylinder misfire. If raw fuel is entering the new converter because it isn't being burned, it will damage the converter.

Let me know.

Joe

Hello!

The P0420 code is the only code given off and I apologize for the confusion by flashing I meant It turned on, it didn’t flash off and on.

I don’t know if it is OEM to be honest but I know it is CARB compliant. So I should be able to have a new one sent?

Hi,

I can tell you a new "aftermarket" catalytic converter is required to meet EPA emissions standards for 25,000 miles. Have you contacted the people that installed it? I would hope they would stand behind it.

Also, the 25,000 miles is a requirement by the EPA. That isn't something that the manufacturer can change. I doubt you put 25K miles on it in a couple of months. LOL

Here is the only issue I can think you may have. The vehicle has a warm-up catalytic converter in the exhaust manifold and then another converter under the vehicle. See pic 1

If the same one has failed again, we need to check a few other things. For example, high fuel pressure can cause a rich fuel mixture. That can damage a converter. Also, even an engine coolant temp sensor can cause issues because it indirectly controls the air-fuel mixture.

I don't know if you have any interest, but the remaining pics below are the directions for the removal and replacement of the converters. I figured I would add them in the event you want to do it yourself.

Let me know if I can help.

Joe

See pics below.

I will definitely have to get in contact with them because I really don’t understand how everything could be perfect to the point that everything went well and even the car read everything working fine and no codes. Even passed smog but then about a month and two months later it resurface that makes no sense to me for it to happen that fast. It was specifically the warm up one that was changed. How would I be able to test if there’s a high fuel ratio mixture?

Hi,

To check the fuel issues, you need a live data scan tool. Once it is plugged in and the vehicle is running, you can tell how rich or lean the engine is running based on what is called short-term and long-term fuel trims. Specifically, short-term fuel trims.

If you have a live data scan tool, let me know what the fuel trims are.

Joe

Hello Joe, I took this live reading after my car was at operating temperature and drove a couple of miles.

The fuel trims look okay. They can be plus or minus approximately 10%. In a perfect world, they would stay at 0%.

Below I attached the diagnostics for the code. Take a look through it and let me know if it is something you feel comfortable doing.

Let me know.

Joe

Hello Jacobandnickolas! I ran the check and both the regular DTC P0420 code and the permanent P0420 code are gone! I’m not sure how haha! Did the car fix itself? LOL

Hi,

LOL, maybe you hit something that wasn't making a good connection. Regardless, this is good news.

Let me know if things change or if you have other questions. Also, feel free to come back anytime in the future that you have questions. You're always welcome here.

Take care,

Joe

Thank you!! I Really appreciate it!!!!

I actually do have another question thats been driving me crazy, my tpms light, VSA light, and SRS light are on and I don’t know why. It’s been like that since I’ve had the car. Everytime I try to reset the tpms/calibrate it, it never does. The tpms just comes back. When I took it to american tire depot they said they didn’t know why it was on and that the wheels didn’t have tpms monitors in within them that my honda has it within the body. How would I fix this problem? Not sure how to approach it

Hi,

It could be a few things. What I need you to do is start a new thread related to this problem. We try to keep the links specific to one topic so they are more helpful to others. I hope you understand.

Here is the link to start a new post. Simply copy and paste your new question and we'll get on it for you.

https://www.2carpros.com/questions/new

I will watch for the new post, and again, I hope you understand.

Take care,

Joe

Definitely understand. thank you!!!