Po421

bige9920 · Oct 3, 2009, 06:28 PM

I read a lot about this. i have a 2006 lancer SE. It has 28,500 miles on it and i threw a 421 code and had it turned off and it came back the next day. I called

and he said that if it is either the manifold or the cat they will replace it on waranty but NOT the O2 sensors?!!? does that sound right to anyone out there. dont you think under the 8 year 80,000 mile emmissions waranty it is covered?

any help with this would be cool.

anyone know any TSB's on this code or if there is recalls for this problem?
Many thanks ahead of time. just got the car and need to learn about it as much as i can!

Ketchup2me · Oct 23, 2009, 10:59 PM

search fool

ThunderOZ · Oct 24, 2009, 02:52 AM

Code P0421- Call Mitsu before you do anything!

bige9920 · Oct 26, 2009, 07:14 AM

yeah Mitsu is going to replace the cat for free.

03dancer · Oct 27, 2009, 07:30 AM

Did they reflash the PCM for u ? Since some lancers have incorrect parameters in the PCM I have the same problem... Did u have an aftermarket exhaust on ur vehicle?

bige9920 · Oct 27, 2009, 10:32 AM

no aftermarket anything,... yet

.

03lances · Oct 27, 2009, 11:13 AM

I took my 03 in awhile back for this. First they reflashed my ecu, then it came back on and they replaced the cat all free no issues since

link62 · Oct 27, 2009, 11:26 AM

when i went all they wanted to do was the reflash but i told them there was the one on the cat so the did that was well... then again my lancer had to be fix at my local mazda service department lol

bige9920 · Oct 28, 2009, 04:23 PM

just got it replaced today! no error codes yet.

now to celebrate!! cheers!