Listsubscriber

I have 200k on this car and it's giving me the codes mentioned in the subject. Two chain shops recommend oxygen sensors, but they can't get them in for 2 weeks. The dealership has the sensors, but they say the problem is the bank 1 and bank 2 cats. They want $1300 for each of the cats!

The dealership replaced all the stuff related to the misfire class action at 190k. As well as egr, timing belt and water pump.

I rode for 10k miles and now 2 new codes.

I can't find any equivalent aftermarket cats online. Also, I'm getting the best gas mileage I ever had in this car at 25-28 mpg (75-90% highway).

What do guys think? O2, cats? Anyone know where to get the aftermarket cats?

Thanks in advance for your help.

DCFIVER

Late model OBD 2 vehicles have very strict testing criteria when it comes to catalyst monitoring. Part of that criteria is to test and retest the O2 sensors(both front and rear) before condemning the cat(s) and setting a Cat code. If the O2s fail, the catalyst monitor will suspend and not run. The O2s will be tested a few more times,and when the PCM is satisfied that they are indeed faulty,you will get an O2 code.


My point? A bad O2 will not set a false cat code. This was not the case in many OBD 1 instances and even early OBD2 (Pre-2000) But is certainly the case in a car of your MY.





But......If the vehicle is not in fuel control(misfires,running lean,rich,etc.....) Then you can get a false cat code. The conditions may not be severe enough to set a code, but they can be severe enough to exceed the capacity of the catalyst event.




At your mileage,you more than likley need new cats,but a scan tool would be needed to know for sure.......

GoLowDrew

Also, those codes does not mean the cats are bad. It just means they are not working as efficient. But is it really the cats? If your car have less miles, I would doubt that they are failing. I don't know how long cats last IRL (never own a car that long).


(my 200K+ mile car does not have any cats).


It could be other things. Maybe the coolant temp sensor is bad. Sending the wrong signal so all the fuel is not burn. Therefore, triggering the code that your cats are failing and not doing it's job.


Just throwing this out there. Are your spark plugs still good? You can check that yourself first.


It seems like these shops just want the easy way, and start replacing stuff, because the code said so. That's a robot mechanic. It does not seem like these guys are thinking....what is the root of the cause?


It's like they are fixing the problem "backwards" first.

Listsubscriber

One of the best forums I ever joined!!

I checked all 6 plus and they looked good. 1-3 were a little more worn than 4-6, but they all looked good. Especially when compared to the plugs before Honda repaired the misfire problem.

I plugged up my ODB scan tool, but to be perfectly honest, I have no idea how to interpret the results.One thing that looked weird was the EGR reading of 99.2%...I would think a new egr valve and gasket would give something different than 99.2%, but I really don't know.

I got two new Honda cats for bank 1 and bank 2 and the codes went away! I already put 1,500 miles on them and the codes are still off. I passed emissions today and I'm happy!

Thank you guys for all your knowledgeable answers!

GoLowDrew