jasrams

My car threw this code and I know it has to do with the cat perfroming below threshold. My question is can I replace the cat with an aftermarket resonator and place the o2 sensor in the resonator. please advise!/

Whatislove

I had the same problem. I replaced mine with a $50 magnaflow cat which then continued to give me that same error code. So I installed a spark plug non-fouler and that solved the problem. I recommend you do this.

These cars are ULEV so they require that california/carb certified $700 cat

lowlife9

this
http://www.robearracing.com/pd-megan...or-cel-fix.cfm

Whatislove

^^that's pretty much what a spark plug non-fouler is with an added 90 degree angle and $25 more dollars.

Allboost18b

The only problem with putting an obd2 sensor into a resonator is that it will kill gas milage. Remember that cats filter the co2 from the exhaust and o2 sensor see how much and how clean the fuel is burning. Generally the problem if an o2 sensor is reinstalled after going bad means its choked full of carbon buildup... Generally i replace with new sensors everytime a cats put on ( if its running the code) although it's not necessary...

seanbev24

^^ The downstream o2 sensor has absolutely no effect on gas mileage. It's only job is to monitor cat efficiency.

Whatislove

I would like to say that's not true. When I had mine 0420 error and before I installed the non-fouler I was getting worse gas mileage.

seanbev24

I imagine that was because of the PCM's reaction to the p0420 code. If the sensor actually controlled air/fuel ratio, the non-fouler trick probably wouldn't be an option. I know some newer cars that have wideband systems use the downstream sensor to fine-tune air/fuel, but in standard systems the downstream is just monitoring the cat.

Allboost18b

He wanted to omitt the cat bud.. And glasspack, instead with the sensor into it. Glasspack/resonators in general only filter noise, cats filter exhaust for emissions. If you just run the sensor after a ressy without a cat, thatsensors goin to get a serious beating wideband or not.... And the second o2 sensor reads the exhaust, which the ecu reads as do i need a little more gas or little more air from what youre telling me, the fact theres 2 on 02 lx's obd2 <-- will mean that it has an effect but not so much as it would if there were only 1. Truthfully, given that an engine is a self running air vaccum, i try to leave the o2 sensors how they are, and when boosting cars i consult a tuner first to see how they affect my engine directly.

Remember this is a fourm, im offering an opinion mixed with my own belief and experience. Weather you follow it or agree with it, is your own choice.