A bit of chronological history (See viewtopic.php?f=12&t=39166" onclick="window.open(this.href);return false; for more detail)
1. Car could barely go 50 miles per hour.
2. A mechanic looked at it and determined that the back pressure test was off the charts. Cut off the cat converter by the second O2 sensor. Looked OK--certainly nothing that would cause back pressure readings to jump off the charts.
3. Removed the front exhaust assembly and noticed the cat converter built into the exhaust manifold was at least 70% plugged.
4. Gutted the plugged cat (very simple procedure, by the way) and acceleration problem went away. Runs smooth and fairly quiet.
5. After approximately 100 miles of travel the DTC P0420 came on.
I'm in the process of establishing baseline MPG.
So, I would appreciate some suggestions: (Would giving you O2 sensor voltage readings help?)
P0420 Code after front cat gutting
P0420 Code after front cat gutting
2003 AWD Vibe, 153K miles.
Re: P0420 Code after front cat gutting
Gutting the CAT is what is causing the CEL. Guessing it will continue to re-appear until the CAT is replaced. Some have had success "fooling" the sensors (search will give specifics). I opted to replace the cat rather than screwing around with the sensors etc.
Pat
Pat
Bare Bones Base, Abyss 2004 Vibe, Debadged, Auto, ABS, GM Performance Supercharger, Injen CAI, 2.3" URD Pulley, Unichip,Tru-Cool Tranny Cooler SOLD
1972 Plymouth Duster 340 (Strip/Street Project)
1972 Plymouth Duster 340 (Strip/Street Project)
Re: P0420 Code after front cat gutting
I would opt for replacing the manifold/cat assembly. The $300 - $500 it would take is cost prohibitive right now.DiveNut wrote:... opted to replace the cat rather than screwing around with the sensors etc.
Pat
2003 AWD Vibe, 153K miles.
Re: P0420 Code after front cat gutting
If you're still working on this. Ad an 02 extender from ebay, or google spark plug anti fouler 02 extender. It will stop your CEL from coming back on.
Re: P0420 Code after front cat gutting
Phew! Your title made me think you had disemboweled a cat at speed on the road. Good to know the facts now!
1997 Civic EX sedan w/auto trans2001 Accord EX sedan w/5-spd manual2009 Vibe 2.4L w/5-spd manual, sunroof, monsoon, GT spoiler, Magnaflow muffler and rolled SS tip, lowered on H-Tech springs, window tint, debadged (save the red arrow!).
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joshuaeb09
- Posts: 168
- Joined: Mon May 31, 2010 12:01 pm
Re: P0420 Code after front cat gutting
Just build your own O2 sim. You can find diagrams online and all the parts you need cost no more than $15. I ran for the longest time on a sim (Full Header = No Pre Cat =P) with 0 issues. All the spark fouler/extender methods will eventually pop a P0420 again. Just make sure you only sim the POST cat O2 since the pre cat O2 is your AFR reading 
2009 Silver Vibe GT AutomaticI/H/E/Unichip @ 93octaneMy Garage : http://forums.genvibe.com/zerothread?id=43521" onclick="window.open(this.href);return false; - Gone (Sold)
2005 Expedition Limited 2WD|4R75W 4SPD Auto|3.73 Gears|I/E|5Star Tuned@ 91|3" Lift/Level - Current Ride
2005 Expedition Limited 2WD|4R75W 4SPD Auto|3.73 Gears|I/E|5Star Tuned@ 91|3" Lift/Level - Current Ride
Re: P0420 Code after front cat gutting
Is "gutting the cat" legal?
2009 Vibe 1.8L Carbon Gray AT Power Pkg 1/12/092003 Vibe 1.8L Neptune AT Mono Power Pkg 1/27/03 [sold 2/2/09]2007 T&C SWB 7/31/07 "Broke people stay broke by living like they're rich. Rich people stay rich by living like they're broke."