So a car salesman sold me a used 2010 Honda CRV.

After 2 weeks of driving it, engine code P0420 - Catalyst System Efficient Below Threshold (Bank 1). came up. Needless to say, this salesman probably deleted the engine code and sold it to me.

After getting in touch with the salesman, he said he will get "his mechanic" to fix the issue.

I spoke with his mechanic and i told him how he will be fixing the issue?

Mechanic said the car salesman told him to put some kind of 'spacer' in between the catalytic convert or something in this nature.

Is this some BS workaround? What are your thoughts? Any help would be greatly appreciated.

 

Yes, that is a BS workaround.

 

The catalytic converter was/is bad. Instead of replacing the converter, sounds like they will just install an O2 sensor spacer.

If you live in an area that requires smog checks, if the smog tech see the spacer, the tech will likely mark it as failed due to tampering.

 

Yup, i've been swindled

 

The good news is you can tell them to fix the failed cat or you will take them to court.

A good lawyer might find enough info about them swindling others that you have a class action lawsuit on your hands.

 

The code would have returned after 2 or 3 drive cycles- the first day or so that you had it. Blanket caution isn't a bad idea when it comes to car salesmen, but in this case it doesn't sound like anything malicious was going on.

The proper fix for a P0420 is most often to have the catalytic converter replaced. The part alone is around $1,000 for a good OE style replacement.

The "spacer" is about $7. It may work, but know that for a commercial repair shop to do this it would be considered "tampering" with the emissions system. The fine is $2500 per vehicle If I remember correctly.

To me I wouldn't consider it "swindling" or a "rip-off" if you were charged a reasonable price- $50 or less and they did what they told you they would do. Evidence being the light/code was gone. But that doesn't mean what they did was right...

 

Well it doesnt seem honest. I believe by you pushing back the sensor by using a spacer, you're still causing issues to your car, am i wrong?
Wouldnt a P0420 cause an eventual clog in your catalytic converter if left untreated?

 

I believe the exhaust manifold for the vehicle is located directly behind the engine correct?
Would this be the part for the vehicle?
https://www.rockauto.com/en/moreinfo...pt=5808&jsn=19

 

If I remember an OEM cat for a CRV is around $2500. any thing after market will not last very long, maybe 2 years or less.

 

P0420 is triggered when the upstream/downstream sensor delta is beyond the set threshold. The primary sensor should see "dirty" exhaust. The secondary, downstream sensor should see "cleaner" exhaust that has passed through the converter under normal conditions. So if the comparison of readings are too close then the ECU assumes the converter is no longer effective at cleaning the exhaust. A bad sensor could be giving an inaccurate reading, but it's usually a material degradation within the converter matrix.

The spacer isn't causing an issue, it's hiding one from the ECU.

These OE cats are backordered or "unavailable" most places I look. There are OE quality ones available in the aftermarket, you're just going to pay for the difference in quality.

 

The ecu is looking for let’s say 97% catalyst efficiency however perhaps the ecu is only seeing 94% as an example and setting the code. Generally 420 is a cat code but could also be a sensor issue, diagnose. If it is the cat, also ask what is causing the cat to become less efficient. Many times burning oil or coolant will cause accelerated wear on the cat. The spacer workaround is fine if actual tailpipe emission isn’t measured and no visual inspection.

 

Just a thought – I bought a used Element (SC) [quite possibly the same engine] six or seven years ago and within a month or two got a P0420.
Reset it and ever since have got the error code every 5 or six months. Everything seems OK. That is six or seven years.

Just a thought.

 

p0420 typically will cycle on/off due to the ecu seeing certain parameters being met or not met. These parameters are based off a # of drive cycles and other events which your daily drive may or may not satisfy.