po422 Catalytic Convert S70 98 NA

[nico416]

I need a catalytic converter for this car. The etest is coming up in the fall, but there is a noise coming from the exhaust leak before the cat that cant be repaired. so im looking for a new part.

Can someone tell me which one will work better for my car? there is only 3$ difference between these. The first one is whats listed through the site for my car, the 2nd is the one my mechanic was ordering for me ended up wanting like 80$ more than i can get it for.

I see FCP only sells the Bosal for 360 with bad reviews, so i figure this magnaflow is my cheapest option to remedy this po422.


When i search for my car it comes up this
https://www.magnaflow.com/products?partNumber=99304HM

It seems like a small cat that 99304hm. So i looked up the 97 850 knowing its the same Cat. and a bigger part comes up.

https://www.magnaflow.com/products?partNumber=99005HM

Is there any reason to not buy the bigger cat, apparently something about o2 not clearing on the bigger cat which i dont understand because the o2 sensors on this car are not even attached to the cat its the piping before and after, which i plan on leaving, just delete the cat and slide this one in.

My s70 i have literally tried everything to get that code fixed, the last 2 months everybody has pointed to getting a new cat, saying yes its rare but mine is gone.

If there is another cat out there that someone recommends please let me know, There was a guy in buffalo with an entire exhaust from the manifold back for 200 but that is really far for me to trek on a used part.

Speaking of used On my other car There is a cat 1997 850 SE wagon but theres 580000km /// 360000miles on it. I do plan on recycling the cat and the sensors before letting the scrappers come take it away. But im guessing this magnaflow option is the best.

Thanks again, This is really the last big issue (for now) that i face.

I definitely learned so much about cars with this 6 grand adventure. I think i would of gotten a t5 if i could go back in time knowing all the stuff i changed i would of rather had a faster car. but oh well. its reliable these non turbos or so they say

[FLXC90]

If you look at the specs, the difference is the exhaust pipe diameter. The 99304 is 2.00" while the other is 2.25" The larger pipe cat lists the 2.3 and 2.4 motors for '98, so I expect it is for LPT and HPT motors, the N/A needs the 2.0 pipe.

[FLXC90]

Looking around, I found reference for Walker brand #99302 replacement cat-$80 at amazon

[nico416]

Just an update

So the muffler shop did fix the original cat. I am praying the light stays off, over 300k and no light does seem promising though.

My noise didnt go away, they claim it could be a wheel bearing, the more im theorizing it does only appear above 50km/h the sound is like an airplane, and does get louder the faster i go.

My main mechanic is on holidays, And id have to drive quite a distance to get it to a guy with used wheel bearings.

[nico416]

wheel bearing fixed the noise i had.

But engine light is back po422 returns. after 950km of driving, about 5 days.

I took photos of what they fixed this latest time.. (I still have the magnaflow cat to use.)








My big concern atleast to what i know which is limiited is I still have no voltage to my rear sensor. I think someone locally here broke my sensor back las tyera when they installed and this code first began i have a feeling the reston im getting this code is because the rear o2 sensor is saying nothing to the computer being broken. (i have litetime warranty on it with fcp but knowing that someone broke it i dont want to go through hassle of warranty).

I have a o2 sensor off my 850 wagon, Its got lifetime warranty with FCP. and that car i see voltage on the rear sensor with Scanmaster, the 98 s70 i do not I used to, before i started fixing all sorts of stuff. This Po422 is a nightmare. I have emissions in a month and well over 5k into this car so i cannot just dump it to get another easily.


So in the shortterm i want to try i guess a used rear sensor to get the voltage back there? (someone told me if my cat is bad its possible thats why theres no voltage there)

Can i cut my exhaust off that car with a reciprocating saw and get the o2 sensor off? I unhooked both sensors.

Can i do this without a hoist, just jacking the car up on jack stands?

Thanks for any and all help with this issue. nightmare and a half. been dealing with it since Febuary..

[FLXC90]

Yes, the exhaust on the 97 850 should be the same as your 98. you could swap out the entire thing. For real low cost, use what you have, or at least until you can afford better. The rear 02 sensor is on the left hand side of the pipe, about midway down the pipe. There is a brace directly beneath it. with the car safely raised on a hoist, or jackstands, it is easily accessible. This would be my first course of action. Then if the code goes away and stays away, done.

You may find the old sensor from the other doesn't fix the problem. If the code returns as P0422, swap your entire exhaust from the 850. I expect you will have to separate it at the junction between the downpipe and the cat pipe in order to remove it from the car, so if your exhaust manifold/downpipe is good on the 98, swap the parts that run horizontal.
If the manifold on your 98 leaks, take that off after the other parts and swap it all.

If as you say, your 850s exhaust is good, and the car is going away, take what you can, free parts is bestest.

[wizechatmgr]

If this is a heated O2 sensor (likely) and NOT a wide-band then you should be able to plug a multimeter into it and verify the heating circuit is getting power at the harness and then continuity of the heating element on the O2 sensor. If it is, then hook up the multimeter to the signal side of the O2 sensor on DC Volts setting and see what, if anything, you're getting there. If you aren't getting anything on the signal side, your life got easier as you just need to replace that O2 sensor.

Would suggest car be running for both, though it is probably only necessary for the last test.