Can I remove the catalytic converter on my 08 XC70?

REnglerth · Post by **REnglerth** » 13 Feb 2019, 07:26

My engine light has come on and is presenting 4 codes; all for the catalytic converter. Can I remove the converter, patch the exhaust and be able to reset the warning light?

Post by **Rattnalle** » 13 Feb 2019, 08:29

No. The car checks the exhaust before and after.

A bad or removed cat will just by itself throw codes. There are however a number of things that can go wrong and throw cat codes even if it's fine. Air leaks for example.

REnglerth · Post by **REnglerth** » 13 Feb 2019, 09:22

When you say air leaks; you mean from the intake? Exhaust leaks?

Post by **Rattnalle** » 13 Feb 2019, 09:35

Either or both. Anything that throws off the measurements. More likely exhaust though if it complains about the cat.

REnglerth · Post by **REnglerth** » 13 Feb 2019, 13:03

I was told there are 3 catalytic converters. 1 in the manifold and the 2 in the exhaust. Is there anyway to figure out which one(s) it is?

Post by **RickHaleParker** » 13 Feb 2019, 13:34

You where told wrong, It is Three-way Catalytic Converter (singular) not three Catalytic Converters.

A Catalytic Converter is expensive and rarely go bad, replacing one should be a measure of last resort. Most of the time it is something else that cause the Catalytic efficiency code to trip.

The code does not mean the Catalytic Converter is defective per se, it means the stuff that is suppose to get converted is getting past the Catalytic Converter. More often then not, this is because the Catalytic Converter is getting hit with more stuff then it can process. In other word the Catalytic Converter is overwhelmed not defective.

Look for the other causes first.

What are the four codes?

REnglerth · Post by **REnglerth** » 13 Feb 2019, 16:28

P0420 & P0430
Catalyst system efficiency below threshold; bank1 & bank2

Post by **RickHaleParker** » 13 Feb 2019, 17:35

P0420 & P0430 Possible sources:

1. Misfiring
2. Leakage in the intake system
3. Leakage in the exhaust system
4. Faulty fuel pressure
5. Uneven compression
6. Anything that messes with the Air/Fuel ratio.
7. Anything that messes with the fuel burn.
8. Damaged catalytic converter.

In short: Anything that will alter the expected chemical composition of the exhaust gases.

REnglerth · Post by **REnglerth** » 13 Feb 2019, 18:10

It runs like a sewing machine. Any suggestions on where to start? I also have seen an aftermarket spacer for the rear O2 sensor mount on the catalytic converter. It’s supposed to create some distance between the sensor and the exhaust, tricking the ECM. Any validity in this?

Post by **precopster** » 13 Feb 2019, 18:17

Validity yes. Premature failure of catalytic converter by doing this, also yes.

It's pretty crucial to report miles on the car as O2 sensors that are inaccurate (particularly pre-cat) can cause these codes. Also have O2 sensors been replaced in service history?