Mitsubishi Eclipse 4G Forums banner

1 - 2 of 2 Posts

·
Registered
Joined
·
1 Posts
Discussion Starter · #1 · (Edited)
Hi all,

First off thank you to all the moderators, creators, and fellow DIY'ers that have contributed to this site as it has served to be an invaluable resource to me this past 5-6 months of diagnosing the notorious "p0421 and p0431" engine trouble codes. This car was given to me as a gift earlier this year and in order to register under my name with DMV I I first had to get this thing I/M ready to pass smog in the most stringent state (Cali) for emission laws. Car was given to me at about 192k miles with no major mechanical defects. Previous owner claimed he had a head job done but don't know at how many miles it was done. I have no mechanical background or previous experience working on cars other than the occasional oil change. This has changed since having to diagnose this trouble code myself and the process and journey it has taken me on. For me knowing that mechanics *CAN be a shady business and dealerships ripping ignorant ppl left and right I knew I was left to figure this out on my own.

It all started with me learning youtube video after another of how an engine works and what the emission system is and the components and sensors involved. I learned how to interpret info off of a OBDII scanner in regards to fuel trims and O2 sensor graphs/ readings and how to diagnose faulty catalytic converters. I researched forums and guides. Any and all info I could find on taking care of this code. I found the service manual on tearstone which I highly recommend for anyone that does work on this car to have (and the best part is its free!). I first started with trying to clean the cat with cataclean. That didnt work. Did a 50/50 mix of paint thinner wedged a rock on the gas pedal to stay at 3k rpm in neutral for 30 min. Still no luck. Switched out the plugs with brand new NGK iridiums.Upon inspection of old plugs cylinders 1-3 had plugs that were fouled with oil. Changed the tube seals and valve cover gasket.(no more oil leak into plugs)Cleaned the throttle body which did have carbon deposit buildup on bode sides of the butterfly plate. Still code didn't clear. Cleaned the intake manifold with CRC cleaner. Cleaned EGR and port. Bought 4 new O2 sensors on sale at rockauto, put them in. Still nothing. I pretty much did everything I could before going the most expensive route of buying a brand new catalytic converter/ manifold. Dealer wants $900 plus for this manifold. Not happening. Just when I felt like giving up I thought of looking for a manifold at a junkyard. Bingo this would be it. I ended up finding one that came off of a car that was crashed at 80k miles for $250. I had to make sure it was a cali car and same model for emissions reasons. Put this bad boy on with a new felpro manifold gasket. Do a drive cycle still engine trips code. At this point I'm really perplexed and just tired of trying to figure this thing out. It had been months of diagnosing and endless drive cycles to no avail. I finally found a post some where on here that this code is somewhat common and that the ecu settings are very strict when it comes to the catalyst emissions readings for the 02. I also discovered that there was a recall back in 2006-07 for these manifolds for this reason and a delaer reflash was also needed. So did more digging and learned that there are these adapters called CEL delete O2 spacers/ adapters that when put in between the O2 sensors would trick the ecu to read exhaust fumes within spec. Bought these put these on and at last finally this it what did it.lol

So these were some painstaking months of troubleshooting and diagnostics but it was so worth it.

Since passing smog and being able to register it under my name I have been doing light mods here and there. Last month an 06 GT was added to my local junkyard. Went the next day of its arrival and was able to get the throttle body and an Injen short ram intake that it had on it. I really came up and lucked out on this one. got the TB for $50 and the Short ram for $15. Guys the junk yard is where its at. Especially if you're like me and aren't strapped with cash to just dump on a car.lol Been ale to buy small parts too from there like a new sunroof switch and the middle clock/compass that went out on mine. I did the TB bypass. Took out the intake manifold resonator and installed block off plate. Just installed an oil catch can yesterday. I have a DC sports CAI coming in later this week it will replace the short ram i have now. Next will be a rre axle back muffler. I am keeping it as Naturally Aspirated as possible for now until I develop the skills to maybe do my own custom turbo.
Also thinking of pulling an engine out of a junked gs just to do an engine overhaul and drop it in later, These are all just ideas, goals, aspirations of mine.

Having this car so far has encouraged me and sparked a new passion and hobby for doing DIY work and tuning/modding. It is very rewarding and satisfying to know that you solved a problem and are rewarded with a better performing vehicle that you put your energy and time into. My gratitude to this site and all those who contribute and share their skills and knowledge with those that don't have the means and resources to take to a shop or pay someone else to do it. I'm just a grateful dude with a new hobby and inspiration. Thank you guys again and especially to all you that have read this post this far. lol Look forward to sharing as I go and meeting/ chatting with you guys.

P.S. If any of you guys are dealing with the cruise control light staying on or randomly lighting up and accelerating out of no where I think I figured this out on accident. When I was putting in the block off plate to the intake manifold I had to unbolt the MAP sensor (left side on top of intake manifold) so the resonator would have enough space to be pulled out without the wire to the sensor being in the way. The sensor had sludge/ carbon buildup and i wiped it clean before bolting it back in. Coincidentally after doing this the cruise control light has not popped up randomly like it used to. Hope this helps someone thats encountering that. I know it was annoying for me.lol

- Tortuga
 

·
Registered
Joined
·
8 Posts
Hi all,

First off thank you to all the moderators, creators, and fellow DIY'ers that have contributed to this site as it has served to be an invaluable resource to me this past 5-6 months of diagnosing the notorious "p0421 and p0431" engine trouble codes. This car was given to me as a gift earlier this year and in order to register under my name with DMV I I first had to get this thing I/M ready to pass smog in the most stringent state (Cali) for emission laws. Car was given to me at about 192k miles with no major mechanical defects. Previous owner claimed he had a head job done but don't know at how many miles it was done. I have no mechanical background or previous experience working on cars other than the occasional oil change. This has changed since having to diagnose this trouble code myself and the process and journey it has taken me on. For me knowing that mechanics *CAN be a shady business and dealerships ripping ignorant ppl left and right I knew I was left to figure this out on my own.

It all started with me learning youtube video after another of how an engine works and what the emission system is and the components and sensors involved. I learned how to interpret info off of a OBDII scanner in regards to fuel trims and O2 sensor graphs/ readings and how to diagnose faulty catalytic converters. I researched forums and guides. Any and all info I could find on taking care of this code. I found the service manual on tearstone which I highly recommend for anyone that does work on this car to have (and the best part is its free!). I first started with trying to clean the cat with cataclean. That didnt work. Did a 50/50 mix of paint thinner wedged a rock on the gas pedal to stay at 3k rpm in neutral for 30 min. Still no luck. Switched out the plugs with brand new NGK iridiums.Upon inspection of old plugs cylinders 1-3 had plugs that were fouled with oil. Changed the tube seals and valve cover gasket.(no more oil leak into plugs)Cleaned the throttle body which did have carbon deposit buildup on bode sides of the butterfly plate. Still code didn't clear. Cleaned the intake manifold with CRC cleaner. Cleaned EGR and port. Bought 4 new O2 sensors on sale at rockauto, put them in. Still nothing. I pretty much did everything I could before going the most expensive route of buying a brand new catalytic converter/ manifold. Dealer wants $900 plus for this manifold. Not happening. Just when I felt like giving up I thought of looking for a manifold at a junkyard. Bingo this would be it. I ended up finding one that came off of a car that was crashed at 80k miles for $250. I had to make sure it was a cali car and same model for emissions reasons. Put this bad boy on with a new felpro manifold gasket. Do a drive cycle still engine trips code. At this point I'm really perplexed and just tired of trying to figure this thing out. It had been months of diagnosing and endless drive cycles to no avail. I finally found a post some where on here that this code is somewhat common and that the ecu settings are very strict when it comes to the catalyst emissions readings for the 02. I also discovered that there was a recall back in 2006-07 for these manifolds for this reason and a delaer reflash was also needed. So did more digging and learned that there are these adapters called CEL delete O2 spacers/ adapters that when put in between the O2 sensors would trick the ecu to read exhaust fumes within spec. Bought these put these on and at last finally this it what did it.lol

So these were some painstaking months of troubleshooting and diagnostics but it was so worth it.

Since passing smog and being able to register it under my name I have been doing light mods here and there. Last month an 06 GT was added to my local junkyard. Went the next day of its arrival and was able to get the throttle body and an Injen short ram intake that it had on it. I really came up and lucked out on this one. got the TB for $50 and the Short ram for $15. Guys the junk yard is where its at. Especially if you're like me and aren't strapped with cash to just dump on a car.lol Been ale to buy small parts too from there like a new sunroof switch and the middle clock/compass that went out on mine. I did the TB bypass. Took out the intake manifold resonator and installed block off plate. Just installed an oil catch can yesterday. I have a DC sports CAI coming in later this week it will replace the short ram i have now. Next will be a rre axle back muffler. I am keeping it as Naturally Aspirated as possible for now until I develop the skills to maybe do my own custom turbo.
Also thinking of pulling an engine out of a junked gs just to do an engine overhaul and drop it in later, These are all just ideas, goals, aspirations of mine.

Having this car so far has encouraged me and sparked a new passion and hobby for doing DIY work and tuning/modding. It is very rewarding and satisfying to know that you solved a problem and are rewarded with a better performing vehicle that you put your energy and time into. My gratitude to this site and all those who contribute and share their skills and knowledge with those that don't have the means and resources to take to a shop or pay someone else to do it. I'm just a grateful dude with a new hobby and inspiration. Thank you guys again and especially to all you that have read this post this far. lol Look forward to sharing as I go and meeting/ chatting with you guys.

P.S. If any of you guys are dealing with the cruise control light staying on or randomly lighting up and accelerating out of no where I think I figured this out on accident. When I was putting in the block off plate to the intake manifold I had to unbolt the MAP sensor (left side on top of intake manifold) so the resonator would have enough space to be pulled out without the wire to the sensor being in the way. The sensor had sludge/ carbon buildup and i wiped it clean before bolting it back in. Coincidentally after doing this the cruise control light has not popped up randomly like it used to. Hope this helps someone thats encountering that. I know it was annoying for me.lol

- Tortuga
I’m reviving this lol, nice post man.
So I’m Having p0341 show up in my car, best course of action would be to find used manifold and the also try it out with o2 spacers?
 
1 - 2 of 2 Posts
Top