tbiggs

Hey guys I have an 05 4g94, i've been dealing with this p0421 problem for 4+ years now. Passing smog usually consists of me just clearing the code and going down there and passing(my emissions are perfect+everything stock) since i'm in cali they give me the full deal, pipe sniffer, odb2, visual etc..

Now I just failed smog twice because odb 2 was not ready. Ouch $30 each time. My question is will the fouler trick fix this? and which 02 sensor do I install it on?

Thanks.

I tried to clear it and drive around until my odb2 was ready but the sel will pop.

03lances

iTrader: (14)

Well not knowing what steps you have taken thus far to try and correct the issue...
Only thing I can say is if your cat is indeed bad and its not a faulty sensor then yes slapping on a couple antifoulers will clear up the code. My question to you though is if the cat is bad wouldn't they still be able to nail you if they take physical exahuast measurements? I dont live in an area that requires smog of any kind so I have never dealt with it before.

tbiggs

^well that's what confuses me.

If my cat is bad why are my emissions ok? I tested twice this past week and I passed the pipe sniffer part. Would the fouler make me fail the sniffer part for some reason?

Ive done no steps other than just deal with having this code for a few years, like I said clearing it before smog and passing with flying colors.

So my question to you is which sensor do I slap the foulers on, I assume a second o2 sensor underneath the car, not the one you see immediately when you pop the hood?

My thinking is why are you(smog/california) gonna beat me out of hundreds of dollars I don't have if my emissions are fine...

thanks!

03lances

iTrader: (14)

The fouler will not make you fail the sniffer assuming nothing else changes. Yes you would put it on the 2nd 02 sensor. They should come in packs of 2. Take the first one your putting on and drill out the hole so the head of the sensor fits through it when you thread it on, then thread the 2nd one onto that.

Couple of old crappy out of focus pics I tool when I put mine on.

tbiggs

ok i will be trying this tomorrow, thanks will post results

invecs

iTrader: (4)

im gonna try this too. i took my car to the smog shop the other week. then the check engine light went on. thank god for the scanner. i deleted the check engine light before i entered the smog shop and hid the scanner in my tool box.

03lances

iTrader: (14)

I have been running with no cats for almost 4 years now with both 02 sensors still attached and no codes so it definately works

Sairo

P0421, that's is also the code that I got. I just check my exhaust pipes and it seems that my front exhaust pipe is causing the trouble. I am just wondering where to get the nut and bolt that holds the pipe and the converter. I have to replace those because they are full of rust.

03lances

iTrader: (14)

IIRC the stock cat has studs that the nut attaches to. If the stud and nut are totally rusted to crap you could cut off the stud and drill through them and just get some nuts and bolts from the hardware store. I gave a member my old exhaust and they too were rusted so bad they broke off when trying to loosen them. In that case we just took it down to the exhaust shop and had the 2 flanges welded together which worked great.

Sairo

Are you referring to the exhaust manifold that has studs? If so, do I need to remove it if the studs are rusted and need to be drilled.

03lances

iTrader: (14)

I was referring to the catalitic converter as I thought that was where you were referring to. Its been soo long since I had stock exhaust its hard to remember. I know you have the manifold which bolts to the downpipe, which in turn bolts to the cat, which bolts to a mid pipe, and I believe that bolts to the muffler right around the rear axle.

I think the manifold has studs as well. Basically if its rusted soo bad that the stud breaks instead of the nut coming loose you would be better off cutting the stud flush with the flange and then drilling it out and using a nut/bolt from the hardware store.

If you can get the nuts off without breaking the studs then you should be good with just getting some new nuts.

Sairo

You are right. I was referring to the Manifold ---> Down pipe ----> Cat connection. I have a bad Down pipe. I haven't check the manifold to downpipe connection if the bolt was embedded. That's my concern now, If the bolt is built within the manifold ( as the picture in the service manual), It gives me more work to do because I am planning to Do it myself.

Do you know what size of nut and bolt that I should get from the hardware store? I want to be prepared before I start to dismantle the exhaust.

What do you suggest, should I replace the O2 sensor too? Because I am planning to replace the down pipe first, then if the code doesn't go off, I will try to replace the O2 sensor. Is it OK if I just replace the O2 sensor connected in the cat, and leave the o2 sensor on the manifold?

03lances

iTrader: (14)

I am almost positive it is. I suggest getting some PB Blaster or Freeze Off and spray those down really well and let them sit over night or at least a couple hours to penetrate the nut. This will dramatically up your chances of getting them off without incident. Another trick if the nut is really stripped is to use a small pipe wrench to try and break it loose. Think about it a pipe wrench is specifically make to grip a completely round surface .

You could replace the sensor or just get the 02 foulers for cheater. Your code is either because
1. The sensor is bad
2. The Cat is bad
3. The Ecu needs reflashed per the recall.

As far as the bolt/nut goes, if it comes to that then you will have had to cut off the old one so just take that piece with you and find a bolt with the same shaft size and just a little longer than the piece you brought in (to account for the piece that was still inside the cat flange.)

Sairo

What is an O2 fouler? Where can I get that?
I just bought a DW-40 Penetrant. It say for rusted bolt and nut. I am planning to spray it every night, until my down pipe arrived. Thanks for the tip, I am going to get a small pipe wrench. Some body told me to get a blue torch, it will help loosen the bolt and nut. Is this good too?

How do I know if my car's ECU was already reflashed. I just bought the car last year. Is there an sticker that says it has been reflashed or programmed?

03lances

iTrader: (14)

This^^ is the spark plug anti fouler. Your local autozone or oreilys should have them on the shelf. WD40 is good for all around stuff but really rusted on bolts I have had much better luck with the stronger PB Blaster and Freeze off penetrating fluids. Freeze off is nice because it literally freezes it while your spraying it on and makes tiny cracks in the rust for the fluid to penetrate deeper.

Heating it up is always an option on this type of stuff so yeah you can give that a shot too.

As far as info on your car just call a mitsu dealership and give them your VIN. If your car has already gone through the Flash then it will be on file. They will also be able to tell you if you can still do this with your car under the recall.

Weird I don't know why it is listing the link twice it only shows one URL in my edit box lol.