Volvo S70 2.5T P0422

Ninjakush · Post by **Ninjakush** » 20 Aug 2023, 09:48

Yes the classic code! been battling this little over a year now, Yes, It's impossible! Last night I took my car to inspection and it failed emissions due to high CO, The car has after market down pipe cat and exhaust, it's 3" all the way through it's stage 3 tuned by a company named auto tech with injectors from the T5R.

So anyways after I got the high CO emissions test I figure I really gotta look into this now, so I swapped spark plugs (BOSCH) , cleaned injectors, swapped the PTC valve, smoke tested the engine and found a bunch of leaks in the intake hose that runs with the MAF, so I fixed the leaks did another smoke test and it leaks nowhere now I removed the battery terminals for 30 mins to reset the computer, I then refuel the car with 98 Octane and take it for a test spin I drove 80 KM and no code appeared, so today when taking another spin to actually see if its OK! It pops the code 0.9 KM into the drive, I don't think too much off it and reset the code using a obd2 scanner, I continue driving for 90 KM and the code doesn't show up?

How do I combat this?

long term fuel trim was at 3.13% the entire drive so it's not like it's adding a ton of fuel either, anyone got any tips / tricks I try...?`/ tired swede

Ninjakush · Post by **Ninjakush** » 20 Aug 2023, 10:01

I'd like to add that the car runs/ drives perfectly! unless you turn on the AC then it starts bogging a bit for 2-3 minutes then its fine.

Post by **Clemens** » 21 Aug 2023, 01:10

What catches my attention first is the downpipe. What kind of Cat are you running? Stock, or a 200 cell FIA conform cat? All others might be reason enough to fail. Also, do you have a way to return to the stock tune?
The T5R injectors are orange. I don't know what comes stock in a 2.5. They should not be a problem, though.

One more thing of concern: Is the PCV system clean? If you don't get good vacum, you might screw up your idle emissions.
If it is clean, the intake manifold gasket might be sucking unmetered air. I had this happen to an old Opel of mine. Never passed CO before I fixed it.
This could also be the reason for the bogging with the AC on. This bigging is not normal, though.

Also, double check all air hoses to and from zhe EVAP canister. I thinknthey are a likely reason for your codes.

Good luck!

Ninjakush · Post by **Ninjakush** » 24 Aug 2023, 06:57

I get good vacum when I do the PCV test, the cat is a 350 cell cat from ferrita (Im gonna double check), Its made by a company who unfortunaly went bankrupt so I cant direct my questions to them, I do not have a way that I can return to stock tune by myself unfortunaly, is there a good way I can check the intake gasket without removing it?

Also I do not receive the engine code/ dtc anymore so i went and tried emissions again and it failed, But however my obd2 scanner is saying that everything is functional, so not sure how I can fail it, But I will check evap vacuums, And also try to figure out a way to check the intake gasket, Still get 3.13 long term fuel trim.
https://imgur.io/D0XUJ41?r

Ninjakush · Post by **Ninjakush** » 24 Aug 2023, 07:26

also another questions, Seeing as I get high emissions (CO) Should the computer in the car not alarm me that there is something wrong with the air / fuel ratio? By some code?

Ninjakush · Post by **Ninjakush** » 24 Aug 2023, 07:53

also remember one more thing, when the engine cold starts, it's sputtering a bit, and may backfire very loudly, could that be one of the reasons, and what would that lead too?

Post by **abscate** » 24 Aug 2023, 08:14

The long term fuel trim tells you the car is running very close to stoichiometric. Simply out, the cat is not covering CO to CO2 so you fail emissions.

Solution. New cat. Cost will tell quality

Ninjakush · Post by **Ninjakush** » 24 Aug 2023, 09:06

CO 2500 RPM 0.7 limit is 0.3

CO normal rpm 900 0.1 Limit is 0.5

Lambda 1.03 limit 0.96-1.04

HC 43 Limit 200

Wouldnt everything else fail if it was the cat?

Post by **scot850** » 24 Aug 2023, 10:26

Have you checked your ETC (coolant temperature sensor)? This will make the car run really rich if it is not sensing correctly.

The backfire, sounds like an air/vacuum leak somewhere. Smoke testing is the most effective way to find it.

Neil.

Post by **scot850** » 24 Aug 2023, 10:27

Have you checked your ETC (coolant temperature sensor)? This will make the car run really rich if it is not sensing correctly.

The backfire, sounds like an air/vacuum leak somewhere. Smoke testing is the most effective way to find it.

Neil.