Sharing a DIY on how to remove the Catalytic Converter for fixing/cleaning and replacing Oxygen Sensors (O2) on Volvo SPA. Mine is 2018 S90 T6 with 82K miles.
Symptoms I had and other info for Catalytic Converter failure :
1- Bad fuel economy and delayed boost
2- Backfires (explosion) sometimes when switching the car on/off
3- Engine noise (leaky exhaust sound near/behind the supercharger)
4- Check Engine light every 1000 miles, if cleared
5- Vida Codes:
A- ECM-P042000 – Catalyst System Efficiency Below Threshold (Bank 1).
Parts needed:
1- Catalytic Converter Cleaner
2- Throttle Body Cleaner
3- Electronic Cleaner to clean O2 sensors (replacement of bank 1 sensor is highly recommended)… You can try cleaning it if you would like to save some bucks.
Tools needed:
1- 4 Jack Stands
2- T50, T30, T27, T25, Torx bit, and 9mm allen for propllershaft 6 bolts.
3- 1/2 or 3/8 extensions
4- 10mm/ 13 mm hex bits and wrenchs
5- 23m Wrench 12 point (6 point is okay but will make your life harder)
6- Flat Screw
7- Impact driver/wrench with extensions and angle sockets (to make your life easier given the pretty tight space)
General comments on the removal process
Important: Car must be cold.
1- Jack up the car on the 4 Jack Stands
2- start the engine and put the transmission on N and release the rear parking brakes (to easy removing the propllershaft bolts
3- Remove both O2 Sensor connector from the engine bay. Refer to my another thread for more details.
3- Remove the cross member bar 2 X 10mm bolts and 2 X 13mm bolts)
4- Remove the propllershaft 6 bolts
5- Remove the exhaust system #8 in the component picture ( 5X 10mm hex nuts) and 2 rubber attachments
6- Remove the aluminum cover surrounding the propllershaft area (3X T30 torx screws) – u shabed aluminum cover/protector
7- (Maybe Optional for XC90) Remove the connector and the bolts holding the black pump just left to the catalytic converter (2 X T27 torx screws- top right and top left)…
8- ( Maybe Optional for XC90) Remove the following two torx screws holding the pump metal base ( 2 X T30 torx screws)
9- ( Maybe Optional for XC90) Remove the two 10mm hex bolts holding the catalytic converter carrier on left side area – item #5 in the exhaust pic
10- Remove the 10mm hex bolt holding the catalytic converter from the left side (driver side)
11- Remove the metal shield covering O2 Sensors ( 2 X 10mm HEX) item #6 in the exhaust pic
12- Remove both Oxygen Sensors O2 (23mm Hex wrench)
13- Remove the metal shield covering the catalytic converter connection with the the Turbocharger ( 1X 10mm or 8mm HEX)
14- Remove the 13mm HEX bolt holding the catalytic converter connection With the Turbocharger. item #3 in the exhaust pic
15- Remove the bottom 2 X 13 mm HEX nuts holding the Catalytic Converter at the bottom.
16- You should be able to wiggle and move the catalytic converter to the back of the car. The space is pretty tight you may have to pull slightly and rotate the catalytic converter back and forth. Follow my picture on this on the last pulling position that was successful. For XC90, you may have more space…
17- After removing the catalytic converter plug your home made smoke machine and check for leaks. Use paint to close all the holes and openings.
The leaks on my Catalytic converter was so obvious after removing the heat cover given the severity of the crack.
What caused the crack?
The low quality welding the Catalytic Converter had. In a nutshell, the factory that supplies Volvo didn’t weld the catalytic converter well enough and didn’t even consider the extreme heat the catalytic converter go through and generates.
After, welding the crack, I cleaned the catalytic converter with:
1- Throttle Body Cleaner (Motul)
2- Catalytic Converter Cleaner (Liqui Moly) – with spray bottle.
I used air dryer and, then, kept the catalytic converter outside overnight. When first I started the engine I had some white smoke due to the chemical used for cleaning and since then everything is great. Fuel economy back to normal. Boost and engine responsiveness is also back to normal… The whole process took two days but I’m glad I did myself at home and saved myself +$2000 to fix a small crack.
Anyway, hope this help the Volvo owners who are experiencing the same quality issue.
Here are more pictures of the removal process and videos (sorry for the quality of pics… But was working under stress hhh):
For more info regarding O2 sensor refer to my thread Volvo S90 XC90 Oxygen (O2) Sensors DIY (SPA)
