S60 - catalytic converter low efficiency.
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Hello,
I just got an error code for low efficiency of catalytic converter. 1/4-1/3 of the cars price. So I was looking if it's possible to disable this check of lower the threshold so I do not get this error message? The error code appears and cleans itself intermittently. The car is a Petrol T6, so no aftermarket catalytic converters I could find exist.
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@Leinth Can you please post a list with all DTCs in the car? How many kilometers do you have on the clock, and does your engine consume oil? If yes, how much? The 3 liter T6 is known for high oil consumption due to low quality pistons and piston rings, which destroys/melts the cat over time. Also loose/broken studs at the exhaust manifold are really common, as well as cracked turbo/exhaust manifolds. Is the car tuned or stock?
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@T5-T6-Schnappi thanks for the reply. No oil consumption at all. The car is from USA. The car is stock. The car is at ~180k kilometers.
I had the cat inspected by a probe and it's not melted/damaged. I was getting and error P0420 and no others If I remember it correctly. I had o2 sensor check and it was working fine, it graph from it wasn't steady. So we added a spacer on the o2 sensor. It "solved" the P0420 error, but now I'm sometimes getting another error related to the o2 sensor. That it's stuck on lean.
The error code wasn't constant, it sometimes appeared when I did longer trips with harder acceleration on the highway. Same as the stuck lean error.
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Lean codes mean there's more O2 in the exhaust gases than the MAF metered. This can be caused by a dirty MAF, vacuum leaks, exhaust leaks, PCV leak, too low fuel pressure, and so on....
So, you should first clean the MAF with special MAF cleaner and don't use "sport" air filters.
Could you also please post the exact temporary and permant codes you have seen since you have that problem? Solving a puzzle without all parts is impossible.
Lean code after hard driving sounds like an exhaust leak, so check the connection between cylinder head and turbo manifold. Burnt gaskets and loose/missing bolts on the manifold are really common on T6s that get frequently floored.
Also check the PCV/oil trap and the small hose from the PCV towards the intake pipe. If your car "whistles" after cold start, replace the PCV.
Also check the duty cycle of the fuel pump and fuel pressure while driving.
What fuel are you using? Anything below 98 octane is a no-go if you floor it on a regular basis. -
@Leinth After thinking a little bit more about your problem, I have some more questions. Are you 100 % sure that your downpipe/cat is still original? Your symptoms are also really typicall for T5s and T6s that got a "High-flow"-downpipe installed, but no proper remap to adress the much faster turbo spool up, which is a 110% guaranty to get lean codes. As you installed a spacer, I'm more suspicious, as this is the standard solution to circumvent this problem. Are you also sure that the O2 sensor is still the factory one? Volvos absolutely don't like aftermarket sensors, especially O2 and MAF, the same goes for aftermarket spark plugs. You also mentioned that the sensor reading is somewhat inconsistent. Did you check the connections and cables between the sensor and the ECM?
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@T5-T6-Schnappi said in S60 - catalytic converter low efficiency.:
@Leinth Did you buy the car with this problem, or did it appear some time after you bought it?
The P0420 code appeared like 3-4 years into the ownership of the car. Most of the issues you have mentioned I have already checked. Haven't checked the piston rings, but as they is no oil consumption there shouldn't be a problem.
Lean code appeared the same or next day I installed the spacer for o2 sensor. The spacer is probably too large/long as the o2 sensors show literary nothing now. You have to high-rev the engine for like 1-2 mins o2 sensor to even start showing something, then it shows a steady graph like it should.
There is no "puzzle" to be solved. I had a decent mechanic look at the car, and his conclusion was that cat started dying.
If it was easy to get to the upper o2 sensor I would have "washed" the cat before adding the spacer.
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@Leinth piston rings are only an issue on engines made from 2010 to 2013, but you still might want to do a cylinder leak test on all 6 cylinders to be sure. A compression test is useless on this engine. My 2010 S60 T6 had a broken piston and worn rings on all cylinders, and still passend 2 compression tests, but failed immediately on a leak test. You might also want to take a look at the outlet valves with an endoscope. These tend to burn and start leaking. This can also cause lean codes, but would also have side effects like random misfiring under load. Loose valve seats are also a rare problem., but really unlikely. The injectors of the SI6 engines are also not of the long lasting type, but a failing injector usually gives "too rich" codes together with misfiring, as they tend to start dripping/leaking.
And as your mechanic is incapable to find the problem, it is some sort of puzzle.
The ECM of this engine has over 300 check routines that give specific DTCs for all kinds of problems, if they occur. So knowing the exact error codes is vital for a usefull fault tracing instead of firing the parts canon and wild guessing. This is why I asked which codes you had, since you are having this problem. Even temporary codes might lead in the right direction, especially if there is a detailed set of freeze frame data stored together with the code.
If you're willing to spend money on wild guessing, you can replace the fuel pressure sensor. This part is infamous for degrading over time and report slightly incorrect data to the ECM which cause all kinds of weird problems. Too low fuel pressure at the injectors is one of them. This is why I suggested to look at the fuel pressure and duty cycle of the fuel pump. To rule that out.
A degrading cat at your milage is pretty unlikely, except the car was driven with really low quality fuel for vast parts of its life.
