O2 sensor issue

[Reaper27]

For the last two months my CEL has been coming on and going off randomly. I usually don't have a chance to get it checked cause by the time I get to somewhere like autozone it goes off but i was finally able to and its throwing a P0134 code. In march I put in a Skunk2 RH and my primary O2 sensor went bad when I installed it. So I ordered a denso sensor for club RSX and installed it and the CEL went off. I was throwing a P0134 code for the primary in march. I had no issues till about 2 months ago and it came on, I was like shit not again but before i could have it checked it went off. Then it didn't come on for awhile but recently it's been getting a lot more frequent and it's annoying plus, maybe it'd just me, but the car drives worse when it's on. I thought it might be a bad connection or it was loose or something but I got under the car and it was tight and the plug was snug. I pulled out the plug and all four prongs were fine. Could it be just a bad sensor? Could the RH mess up the primary? Has this happened to anyone before? Also has anyone returned something to CRSX?

[AKEP]

have a tune?

[Reaper27]

No it's not tuned yet unfortunately. I haven't had the money or time to spare without needing my car to get it flashed or to get KPro. Noob question tho, can u tune a stock ecu and would that fix the problem?

[Civic5lug]

RH and no management.....thats your problem. Your going to continue to burn through o2 sensors bro. No there's no way to "tune" the stock ecu.

[Reaper27]

RH and no management.....thats your problem. Your going to continue to burn through o2 sensors bro. No there's no way to "tune" the stock ecu.

Damn, that's what I was afraid of. So if I reflashed it would it keep it from happening? I don't really have the funds right now for Kpro

[Civic5lug]

Damn, that's what I was afraid of. So if I reflashed it would it keep it from happening? I don't really have the funds right now for Kpro

IMO you'll have better luck. What grade fuel are you running? maybe try a high grade also.

[Reaper27]

IMO you'll have better luck. What grade fuel are you running? maybe try a high grade also.

It's def not the fuel. I've ran nothing but premium in it since I bought it. Once I reflash would I be able to have it more custom tuned? Or can I only do that with Kpro?

[Civic5lug]

It's def not the fuel. I've ran nothing but premium in it since I bought it. Once I reflash would I be able to have it more custom tuned? Or can I only do that with Kpro?

Thats only avaliable with Kpro.

[Reaper27]

Ok, that's what I thought but wasn't sure. I'm going to try and reflash it before the end of the year. Will I have to get a new O2 sensor or will reflashing the ecu fix the problem?

[AKEP]

need new o2 sensor, and kpro.

[Reaper27]

need new o2 sensor, and kpro.

Will reflash not help?

[AKEP]

it could. it counts towards a kpro purchase as well. still need an o2.

you just cant tune on a reflash. thats all.

[Euro-Yellow-Ep3]

I had no he same issue when I installed my RH. Only my issue was I only had on defouler on the second o2, then when I put 2 defoulers on the issue want away. And I haven't had a cel in 6 months.

[AKEP]

*nvm i see what you meant*

[Reaper27]

it could. it counts towards a kpro purchase as well. still need an o2.

you just cant tune on a reflash. thats all.

Ok, thats what I was thinking. I'm prob going to reflash in December when I can have some down time for my car, hopefully I can get Kpro not too long after that

[Civic5lug]

Ok, that's what I thought but wasn't sure. I'm going to try and reflash it before the end of the year. Will I have to get a new O2 sensor or will reflashing the ecu fix the problem?
Yes you'll still need to replace the o2.

and now your ecu doesnt see the afr? i bet your ecu is running in open loop right now...
The secondary doesn't contribute to the Air Fuel at all. It only tells the ECU the cat is working. The primary calculates the Air Fuel reading.

[AKEP]

*nvm he meant 2 on the secondary. thought he put one on both sensors lol*

[StreetAddict89]

Good Information.. im having the same problem.. which one is the second sensor the one closer or further from the engine?

[Civic5lug]

Good Information.. im having the same problem.. which one is the second sensor the one closer or further from the engine?
The farthest from the engine is the secondary.

[Reaper27]

See that's what's odd, my secondary is fine. Skunk2 provided a defouler with the header and it works great so far. When the code and light come on it's for the primary. I guess it just doesn't make sense to me since even with having a stocker header and cat on it the primary sensor is always before the cat so it's before the gas can be filtered. If this is so then why does it mess up the sensor? Wouldn't it be the same with a RH and without? Idk, maybe that's a stupid question but it just bugs me

[AKEP]

theres pressure from gas not escaping through the cat as fast as its leaving the engine. by the time the gas gets to the stock o2/cat its cooled off a bit and at stoich, which burns at the normal operating temps (for the o2 sensor).

when you're running around without a cat and a tune, the exhaust gases are escaping the collector of the race header much faster, and slightly leaner (hotter). shit is burning up your sensor. it only operates at a certain temperature range. start cooking that thing and it stops working. it stops working, you go into open loop. you go into open loop, your car stops the fuel compensation for the fuel map and you stay lean.

being super rich would also foul it out. and you can separate the wires from the sensor internally if you twist out the sensor without unclipping it from the harness and not being careful. also getting any kind of lubricant on it will mess it up (anti-seize, wd-40). they withstand a few hundred degrees of burning gas but they are sensitive to much more. your not even supposed to clean it...

[Reaper27]

theres pressure from gas not escaping through the cat as fast as its leaving the engine. by the time the gas gets to the stock o2/cat its cooled off a bit and at stoich, which burns at the normal operating temps (for the o2 sensor).

when you're running around without a cat and a tune, the exhaust gases are escaping the collector of the race header much faster, and slightly leaner (hotter). shit is burning up your sensor. it only operates at a certain temperature range. start cooking that thing and it stops working. it stops working, you go into open loop. you go into open loop, your car stops the fuel compensation for the fuel map and you stay lean.

being super rich would also foul it out. and you can separate the wires from the sensor internally if you twist out the sensor without unclipping it from the harness and not being careful. also getting any kind of lubricant on it will mess it up (anti-seize, wd-40). they withstand a few hundred degrees of burning gas but they are sensitive to much more. your not even supposed to clean it...

Ok I see. No haha, I made very sure that nothing got on the sensor and that I didn't touch it when I was installing. I was also wondering tho, are there any aftermarket sensors that can withstand the heat? I'm going to be reflashing soon but when I do if I already have to buy a new sensor i might as well upgrade if possible. My other question was, if the CEL is not on is the car still in open loop mode? or does it switch back over when it goes off? Thanks for all the help and info guys.

[hyu]

Im having issues with my downstream secondary o2 sensor. Im guessing if I buy a defouler it would lean it out. Im on a aftermarket header and a high flow cat. Lol never got around to buying the defouler. (Im guessing the right angle one from cep3) would work?

Sent from my autocorrect butchering device

[AKEP]

the second one doesn't change afr, its just there to tell you you're high flow "cat" isn't working as good as a stock cat. a defouler will fix that CEL as well.

[BeaterEP]

So wait, maybe I'm misunderstanding; are you guys all saying that running a RH on a stock motor requires a tune in order to avoid burning out the primary O2?

That seems...odd. I'd always thought that as long as you ran a defouler on the secondary you should be OK. :shrug:

[Popeye]

I'm wondering the same thing as you, Beater. I did a search, and came across this search. I have a header and test pipe, but DAMN sure aint going to install ANYTHING if it's just cause me to go through O2 sensors every couple of months. Im also not going to buy KPro just so I can install a test pipe. Seems kinda rediculous to me.
What do the smart people say on this issue? Do you REALLY need to spend $1000 just to install a $100 part?

[AKEP]

So wait, maybe I'm misunderstanding; are you guys all saying that running a RH on a stock motor requires a tune in order to avoid burning out the primary O2?

That seems...odd. I'd always thought that as long as you ran a defouler on the secondary you should be OK. :shrug:
the seconary o2 sim just pulls the secondary o2 out of direct exhaust flow. therefore, saving you from a CEL about the CAT not operating. the primary is closer to the engine, and since the exhaust is running unimpeded, its A LOT hotter when it gets to the primary. untuned, gets burnt up.

I'm wondering the same thing as you, Beater. I did a search, and came across this search. I have a header and test pipe, but DAMN sure aint going to install ANYTHING if it's just cause me to go through O2 sensors every couple of months. Im also not going to buy KPro just so I can install a test pipe. Seems kinda rediculous to me.
What do the smart people say on this issue? Do you REALLY need to spend $1000 just to install a $100 part?

smart people say, "get reflash/kpro and tuned." you don't NEED to spend 1k to install a $100 part. but it would only benefit you to do so.

[Popeye]

Yeah, you cleared a LOT of stuff up for me earlier.
It just seemed like 99% of people's response for ANY mod is "get KPro." Sure, I know it's supposed to be bad ass and all. But $1000 is a LOT of money to most people. To ME, there are 2 kinds of owners....#1-the kind that bought an older Civic because it was the best he could afford with the money he had. And #2-the enthusiast that has the $1000 to spend on an engine management system because he loves tuning Civics. I just get kinda irked seeing everyone's response to EVERYTHING being "get KPro." I know, I know...I am acting like my p***y is hurting. Kinda. I realize there are 2 sides to stuff like this, like I just stated. I just think it's crazy to expect someone to spend $1000 on KPro to bypass a possible CEL because they installed a $100 part. If it's not crazy on the person that said it, then it's crazy on the aftermarket sector for making that happen. (I know, it's actually "genius" marketing. But is it if it's 2 different companies that aren't associated at ALL?) Which is why I asked my question. I don't want to be like someone else that has to keep replacing O2 sensors because I didn't spend the $1000 on KPro, you know?
Ok, I'll go put my tampon in now...

[05 hatch]

Just get the right angle defouler, it's what I had before my EMS. I bought it on eBay, it solved me cel with a test pipe. I never burnt an o2 sensor up.