Finally fixed the P0420 CEL code (it was the Catalytic Converter)

[calavish]

I have a 2005 Vibe Base FWD with automatic transmission 99,340 miles. Over the last 6 months I've had the Check Engine Light coming on with with P0420 Catalytic Converter Lean Bank 1 and it was driving me crazy. I'm a DIY car guy so I did my research and started with the obvious,,,, cleaned the MAF and then I changed the Intake Gasket from the original black gasket to the Toyota Orange Gasket $7, then changed plugs to the preferred NGK iridium plugs $34, then replaced the downstream O2 sensor $51, then replaced the MAF sensor $23, then replaced the upstream A/F O2 sensor $85, with each repair light came back on with same code about a week later. Then I tried Mr Gasket CataClean $20, but it didn't work in fact now the CEL code could be cleared and it would come back on in the next to trips in as little as 10 miles. Next on my list was to attempt to clean the Catalytic Converter by removing the section of pipe between the Exhaust Manifold and the muffler including the 2 cats and the resonator using detergent, but decided instead to replace that same section with a Direct Fit two piece pipe section made by Eastern Catalytic (the part number is 40407) because the price was right $265 including shipping FedEx (after using a 8% coupon). Compared to the Toyota Part this was a really good deal and it fit perfectly (removal and installation in under 3hrs). I cleared the codes and the light has stayed off for the last couple of hundred miles. The system has a 5yr 50,000 mile warranty so I think it was worth the price. BTW if you want to try to replace it yourself with any direct fit exhaust you should know the AWD Vibe has a different part number and shape to the rear pipe.
INSTALLATION INSTRUCTIONS:
Again I installed this on a 2005 Pontiac Vibe FWD Base (same as Toyota Matrix) in under 3 hours. Best way to remove/install is to jack up the whole car and support with 4 stands. I was changing oil and rotating tires too so while it was up in the air I replaced the cats and resonator with the Eastern 40407 direct fit. Job was easy with the engine cold. Go into the Passenger compartment and pull up the carpet on the left side to unplug the O2 sensor wire and push it and the rubber grommet through the floor panel hole. Remove O2 sensor that goes through the passenger side floor w/ special O2 socket or a big box wrench and set the sensor some where safe. Spray the 14mm bolts two at each end of the pipe flanges with WD40 and 5 minutes later they come right off (keep the 4 bolts inside their springs for installation). You will need a lot of 3/8" socket wrench extensions to reach the front bolts. Remove cross member support w/two 12mm nuts, spray a little WD40 on the rubber hangers and the old pipe slides right out. Make sure you leave the rubber hangers connected to the car. I left the front steel mesh gasket in the exhaust manifold. It was in good shape and I had no way to get it off (it doesn't leak so it was a good decision). To prepare the new pipes install the included steel mesh gasket over the pipe stub at the rear of the new pipe section using a small wooden board and a hammer to tap it gently into place. Also remove the O2 sensor hole plug (it should be loose). Then put the 2 sections of pipe together and put the included muffler clamp on the center connection loosely so its where you need it when you need it. Slide the sections together so the pipes are shorter for maneuvering the pipes into position. While feeding the front cat up towards the exhaust manifold connect the rubber hangers to the new pipes. Now the system is hanging in place and you can slide and rotate the two sections apart a little until the length is correct and the two end flanges are lining up properly to the bolt holes. Starting at the front and using the bolts w/springs you removed to install the new system use a 14mm socket at the end of the long 3/8" extensions, push to compress the springs while turning the socket in the clockwise direction. Your trying to get the threads of the bolts to catch the threads in the exhaust manifold flange. If you have a 3/8" air wrench connected to the end of the long extension this step is a breeze. Torque these two bolts to 32 lb/ft (I tightened mine to 35 lb/ft to make sure I was contacting the old gasket). Now install the 14mm bolts w/springs to the rear muffler pipe flange the same way you did the front bolts only using a shorter 3/8" extension (air wrench comes in handy here too). Torque these two bolts to 32 lb/ft too. Now look at the clearances around the entire length of the pipe and heat shields. You may be able to move the pipes around a little while the center connection is floating lose. When your happy with the overall alignment push up just a little where the two pipes sections slide together and position the included muffler C-clamp close to the overlapping edge of the junction of the two pipe sections and tighten the 13mm nuts until both nuts are equally tight and the clamp is compressing the overlapping pipe around the inner pipe snuggly. Install the cross member support with the two 12mm nuts and torque nuts to 22 lb/ft. Now put a little anti-sieze compound on the threads of the O2 sensor you removed and reinstall it into the new pipe torqueing the sensor to 22 lb/ft. Thread the wire through the hole in the floor and press in the rubber grommet to keep rain water out of the passenger compartment. Go inside the car and plug in the O2 sensor wire connector and put the carpeting back in place. Start the engine and listen for exhaust leaks (this system will sound a little different). If all sounds smooth and no loud ticking noise then clear the codes on the PCM by either disconnecting the battery for 10 minutes and then reconnecting it or use a code reader to erase the codes. Then lower the car and cleanup the tools around the car before test drive. That's it. BTW I didn't have to modify anything during the install. Everything just fit my Vibe which is really a rebodied Toyota Matrix and shares drive train with Toyota Corrolla also.
Hope this helped you.

[joatmon]

That's a great price for a bolt in direct fit replacement, thanks for the source and part number

[tpollauf]

Welcome to GenVibe That's quite an impressive "first post" you made there! Now show us what you drive and if possible, some pics of this repair to go with your testimonial. Great job.

[vibrologist]

Welcome to GenVibe, cavalish!
Indeed, this is an impressive entry!