2.0L RV6 Looking for 2.0L Downpipe BETA Testers

[long_meats]

Well guys hate to report in, but I got the CEL (P0420) yesterday while out with a friend. It happened around 450 miles.

I'm guessing the colder weather has something to do with it. I forgot if you mentioned already, but you have the catted downpipe correct? Do you have any other aftermarket power mods? RV6 sent me a short spacer so I'll update here if that helps.

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[FrostyTree]

I'm guessing the colder weather has something to do with it. I forgot if you mentioned already, but you have the catted downpipe correct? Do you have any other aftermarket power mods? RV6 sent me a short spacer so I'll update here if that helps.

Who knows, the weather fluctuated from cold to warm the 2 weeks its been on. Its Texas. It was raining and in the low 40's the day it came on. Besides K-tuner this is my only power mod. Yup catted on stock exhaust. I reset it for now. Will email Rv6 at some point today.

 

[long_meats]

Who knows, the weather fluctuated from cold to warm the 2 weeks its been on. Its Texas. It was raining and in the low 40's the day it came on. Besides K-tuner this is my only power mod. Yup catted on stock exhaust. I reset it for now. Will email Rv6 at some point today.

And your O2 sensor is plugged directly into the downpipe (with no defouler/L-spacer right)? They said they'll send me a short spacer, so hopefully that will be within range of the sweet spot to avoid flagging anything. Will keep ya'll posted.

 

[long_meats]

So on the way home from work the P0420 flagged again. I had the downpipe for at least 3-ish months before that code flagged for the first time, and then it flagged again a week later, so it seems the colder winter weather must be a factor when the O2 sensor is directly connected to the downpipe.

Luckily I had the short spacer that @RV6 sent waiting for me in my mailbox when I got home, and just installed it along with resetting the ECU. Will report with future updates.

 

[long_meats]

So on the way home from work the P0420 flagged again. I had the downpipe for at least 3-ish months before that code flagged for the first time, and then it flagged again a week later, so it seems the colder winter weather must be a factor when the O2 sensor is directly connected to the downpipe.

Luckily I had the short spacer that @RV6 sent waiting for me in my mailbox when I got home, and just installed it along with resetting the ECU. Will report with future updates.

So unfortunately the CEL already came on again, but this time it was back to the ol' P0139 (with the O2 sensor plugged into the short spacer).

@RV6 Do you have any even shorter short spacers available lol. There really seems to be a tiny margin of error to find the right sweet spot where the O2 sensor goes where neither code flags, while also factoring for the seasonal temperature changes.

 

[FrostyTree]

So unfortunately the CEL already came on again, but this time it was back to the ol' P0139 (with the O2 sensor plugged into the short spacer).

@RV6 Do you have any even shorter short spacers available lol. There really seems to be a tiny margin of error to find the right sweet spot where the O2 sensor goes where neither code flags, while also factoring for the seasonal temperature changes.

Damn it, guess I'll wait a bit before requesting a space. To answer you earlier question, yes my sensor is connected directly to the pipe with no spacer.

 

[long_meats]

Damn it, guess I'll wait a bit before requesting a space. To answer you earlier question, yes my sensor is connected directly to the pipe with no spacer.

So it took less than 24 hours for the P0139 to flag with the short spacer, and a week to flag the P0420 again without any spacers, so perhaps the ideal "sweet spot" is closer to the to where the O2 sensor is without the spacer, but just a tiiiny bit more further out.

So I just came up with an idea: When I tried it without using the spacer, I had the O2 sensor tightened all the way in. So I will try unscrewing it outwards 1 full turn and see how long it can go without flagging the P0420. If that doesn't work, then I'll unscrew it for another turn outwards.

Will do that now and keep ya'll posted.

 

[a c i d.f l y]

Yeah, I'll let you play around with it. I'm tired of pulling it off and on. Will wait for it to warm up again.

Texas weather, man. The cold temps definitely the primary reason for it flagging. Need to run some logging, but I've just been really lazy about doing it.

 

[long_meats]

Yeah, I'll let you play around with it. I'm tired of pulling it off and on. Will wait for it to warm up again.

Texas weather, man. The cold temps definitely the primary reason for it flagging. Need to run some logging, but I've just been really lazy about doing it.

I meant to update earlier, but I unscrewed the O2 sensor out just one turn from the downpipe and it felt a little loose and wiggly.

I figured that isn't ideal, so I went to Lowes and grabbed some flat metal washers to fill up the small gap so the O2 sensor will still have a surface to secure up against.

Right now I only used one 14ga washer, and will keep this updated.

 

[FrostyTree]

I meant to update earlier, but I unscrewed the O2 sensor out just one turn from the downpipe and it felt a little loose and wiggly.

I figured that isn't ideal, so I went to Lowes and grabbed some flat metal washers to fill up the small gap so the O2 sensor will still have a surface to secure up against.

Right now I only used one 14ga washer, and will keep this updated.

Thanks man, I have had it come back on twice more. Once at 168 miles, the outside temp was 75f that day. It came on again this morning at 241 miles and the outside temp was 41f. The common thing for me, was that it was raining out each time, just a light rain. So my thought is that its the high humidity maybe throwing things off just enough. Have you noticed what the humidity is like when yours comes on?

 

[long_meats]

Thanks man, I have had it come back on twice more. Once at 168 miles, the outside temp was 75f that day. It came on again this morning at 241 miles and the outside temp was 41f. The common thing for me, was that it was raining out each time, just a light rain. So my thought is that its the high humidity maybe throwing things off just enough. Have you noticed what the humidity is like when yours comes on?

That's an interesting theory, so I don't exactly recall if it rained the day my CEL came on for P0420, but I don't remember it raining and I also checked the weather for that day and it was supposedly sunny (according to weather.com).

I haven't had the P0420 come back on since that one time but hopefully my washer solution will do the trick, but if it flags again I will be sure to report the humidity.

 

[Apollo!]

Does anyone have stock intake and get these P0420 or P0139 flags? I'm saving up to get one in a couple of months...

 

[TiceKustoms]

What code are you getting?

P0139
HO2S B1 S2 Slow Response
HO2S S2 Slow Response

 

[RV6]

CEL came on within 40 miles after catless downpipe installation. Not sure what to do.


2018 EX Sedan 2.0L 10k miles.

P0139
HO2S B1 S2 Slow Response
HO2S S2 Slow Response

Try turning the defouler in 2 turns.

So unfortunately the CEL already came on again, but this time it was back to the ol' P0139 (with the O2 sensor plugged into the short spacer).

@RV6 Do you have any even shorter short spacers available lol. There really seems to be a tiny margin of error to find the right sweet spot where the O2 sensor goes where neither code flags, while also factoring for the seasonal temperature changes.

That's an interesting theory, so I don't exactly recall if it rained the day my CEL came on for P0420, but I don't remember it raining and I also checked the weather for that day and it was supposedly sunny (according to weather.com).

I haven't had the P0420 come back on since that one time but hopefully my washer solution will do the trick, but if it flags again I will be sure to report the humidity.

I do not have a shorter defouler. Looks like the untuned people might have to use a bunch of tricks get no CEL. It seems every car is different. Our test car is still problem free with the original defouler.

 

[a c i d.f l y]

Update. Since the temp rose above 60F the CEL went away. It was definitely below 50F when it came on, and humidity was indeed high. We'll see over the coming months, and summer time, if higher temps have any other adverse effects. My inspection is in August, so hopefully not.

Just to supplement and keep all factors in one post, I have the K&N Intake with KTuner basemap tune, Stage 2 Throttle Response, running 93 octane.

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