P0420 After VVT seals replacement

[vtl]

Ok, made the VVT adjustments, pretty straight forward. Just had to disconnect battery to reset adaptation before checking it after each adjustment.

Bosch ME7 does VVT test every time engine start. No need in disconnecting the battery.

[nliutilitt]

That's what I did initially, but adaptation didn't reset on engine start and reving to 1500. Almost over adjusted the intake. disconnecting the battery updated the adaptation angles after each adjustment.

[nliutilitt]

new O2 sensors in... Volvo sure knows how to make it difficult to access.

Signal is still same as before it seems. don't notice any real changes. Old sensors seem alright?
Double checked the hoses buttoning up after VVT seals, all seemed in place. Will check the hoses again in the morning.

old B1S1 sensor

b1s1.jpg (125.17 KiB) Viewed 199 times

old B1S2 sensor

b1s2.jpg (158.16 KiB) Viewed 199 times

[abscate]

The OXS get old and slow after 100,000 miles. Visual doesn’t really tell you anything.

[nliutilitt]

Well, over 300 miles after replacing both O2 sensors, pre and post cat. Still getting P420 sporadically, Once ~200 miles after new sensors. Again just ~30mile after clearing that. Right now going on ~130, with a P0420 pending but not tripped the light yet.

From live data everything seems fine with the O2 sensors at least.

Upstream shows Lambda, so should be 1, or very close to it. Which it is generally, never varies more than +/- 3%.
Downstream passes OBD test, but hovers near 0.1~0.2v, occasionally goes up to 0.7~0.8. when it should be settling to ~0.45v from what I gather.

Otherwise there isn't any power loss or poor MPG.
LTFT looks in order, 0~5%, about normal for this time of year.
MAF looks in order for this time of year

I guess it's either wiring issue or Cat going bad. Not sure what else it could be.

[nliutilitt]

Got under and checked the temp at front and back of converter. with coolant temp at 90 and idle 650~660 rpm, ~115c entering the converter, and ~90c exit from converter. I believe the exit side should be hotter than entrance side? That confirms cat going bad I guess?

[jonesg]

Got under and checked the temp at front and back of converter. with coolant temp at 90 and idle 650~660 rpm, ~115c entering the converter, and ~90c exit from converter. I believe the exit side should be hotter than entrance side? That confirms cat going bad I guess?

yes, it should react and increase temperature at cat exit.

[dikidera]

That idle looks rather suspicious, these engines always idle at 750rpm. Was true for my 4 cylinder p1 volvo and same for 2.4 s60

[nliutilitt]

This one has been idling at 640~680 for 6 years. varies a little depending on the gas station I last fueled at. but always ran smooth.

[vtl]

That idle looks rather suspicious, these engines always idle at 750rpm. Was true for my 4 cylinder p1 volvo and same for 2.4 s60

2.5T idles at 650.