I posted this over in the Engine mgmt sub, but this is my home, so it's going here too


Long story short:

That time of year has come, where I need to put the car back to stock to pass emissions inspection. This is the first year since going turbo (3 years ago) that I've actually had to go through this process, as there was a loophole that since has been closed.


Anyway, got most all of my stock stuff back on, injectors, map sensor, stock ECU, EGR ect ect. The way I designed the kit was to only require swapping of those crucial parts. The charge piping gets unhooked from the throttle body, and the rest of the kit stays in place. I made sure to weld extra bungs into my downpipe/exhaust to simplify this process once a year so both stock sensors, as well as my wideband are always along for the ride.


Headed out for a drive cycle to set readiness monitors and saw p0133 hit the pending on my scan tool fairly quickly. Reset the ECU, same thing.It's a 2 trip code so it will always pop on the second drive cycle after it sits in pending during the first.

The steps to troubleshoot this code are pretty cut and dry from Honda, either the monitor sets, or it will throw this code (primary sensor slow to respond)


I decided to get under the car this afternoon before throwing a possible wasted $100 at the car on a new sensor if it in fact doesn't really need one....for the 1 day I year it's in use.

Noticed that the bung I used while building my downpipe has the primary sensor stepped a decent distance off the exhaust stream (similar to what people do with de-foulers to fool the rear sensors)and this has me thinking. I'm wondering if my placement of the sensor is what's causing the "delay" back to the ECU and triggering the DTC, rather than a faulty sensor.

To my understanding the "slow to respond" is essentially the ECU not seeing the voltage swing within X amount of time.

Anyone else have any experience here? Am I crazy for thinking this? Figured it'd be cheaper to toss a flush mount bung into my downpipe than it would be dropping the $100 on a new sensor, just to possibly be in the same situation.

Pic of current placement below:

 

That really shouldn't affect it. Those sensors go bad all the time. Borrow one from a buddy and see if it changes things.


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is that for your primary o2 if so it will cause problems so will a cheap part store replacement sensor I had the primary doing that after the car was hot found a used o2 sensor and it fixed if its the secondary you are correct you want it out of the exhaust stream so it looks like the cat is doing its job

 

The picture above is of my primary sensor, it is an OEM unit, not a replacement.

My concern is that I'm getting the code because of the bung I used, as it has the sensor backed off a bit, similar to what's done with the rear sensor.

 

yes that is not the bung to use on your primary. its the problem sad to say you need one much shorter perhaps you can cut it down as long as there are 1/4 of threads it will hold but only temporarily. I feel your pain I too am facing the dreaded inspection and I have to depin some of my harness as I have moved things around for a fuel trim switch and a cooling fan problem it sucks. on that note if you can get the ready codes to set try going somewhere and not turning the car off tell them the battery is dead. I did that the last time because I broke my stock o2 sensor and couldn't find a cheap oem that's how I got past it also what you could do is use the narrow band emulator coming off your wide band it would also tell you if that is the problem and its what I do when I pull my aem I switch from my 5v source to the 1v output.

 

That's my plan of attack, going to cut that down as close to the pipe as possible to get the sensor closer to the exhaust stream.

 

Yeah I've typically only seen the extended bungs used on the secondary sensor to trick the ECU out when there is no cat. Spacing the sensor tip out of the direct stream like that allows the secondary sensor to still get up to operating temperatures but keeps it from seeing all the unburnt fuel in the stream due to the lack of a cat. I've never seen one on a primary sensor and would imagine that it would play a bit of havoc on the OEM ECU.

 

I honestly never even thought about it when welding the DP up. My rear sensor is stepped back with 2 de-foulers, and my catalyst monitor sets no problem.

The bung I used for the primary is just a generic Innovate bung that they include with wideband kits and what not. it's over an inch long.

I'm going to cut it down as close to flush as possible, and re-test.

 

Update:

I took the midpipe off the car, cut that 02 bung almost flush. Just reinstalled and took the car out, all monitors set and CEL free in under 10 mins of driving!!!


Time to get my inspection sticker...with my entire turbo kit hanging off the front of my engine

F@ck yea


P0133: 0

Illest: 1

 

Nice.

Yeah they look at me weird when I pull in with the blower still mounted. Its like they're thinking, "What a waste of my time... no way this thing will pass!"