Fuel trims, dead converter?

Disclaimer: Links on this page pointing to Amazon, eBay and other sites may include affiliate code. If you click them and make a purchase, we may earn a small commission.

east302

Full Access Member
Joined
Dec 21, 2016
Posts
1,630
Reaction score
1,516
Location
Mississippi
Truck is a 1998 K1500 (350) with 225k and it’s had a rough life. It’s my teenage son’s truck, so I’m of a “keep it going long enough until he’s out of high school” mindset versus my Tahoe.

The left head cracked and locked up #5, so I replaced that with a reman head. The right head was also cracked but wasn’t leaking (yet) so I swapped it as well. It must have overheated when the previous owner had it.

It took about two hours to burn the coolant out of the bank 1 exhaust when I started it up after the repairs. It has a true dual with a small crossover before the mufflers. Coolant was dripping out of the exhaust flange downstream of the catalytic converters, so…yeah.

Here is a plot of the bank 1 (which had the hydrolocked cylinder) and bank 2 O2 sensors. Am I seeing a dead cat on bank 1 and a good one on bank 2?

The flange downstream of the cats (which is upstream of the bank 1 downstream oxygen sensor) is shot; you can feel the exhaust coming out of it after the coolant finished leaking from it. I’ll look for another gasket this week and swap it out. Kind of hoping that it remedies everything but you know how that goes.

Would this exhaust leak downstream of the cats (and upstream of the downstream Bank 1 O2 sensor) cause these readings or did the converter say “I’m out of here” after getting flooded with coolant steam?

41591F6F-903C-4A82-BABF-40EBC2E7560C.jpeg
FDBC6920-F83F-458D-9CD3-B5E62E74060C.jpeg

And as for negative LTFT, can y’all help me interpret it?

DDCA1944-F2A7-4164-B2F3-1AC6CC697B92.jpeg


No DTCs are stored. Thanks for any help, I’m looking forward to finally getting this out of my garage :)
 
Last edited:

Forum statistics

Threads
132,764
Posts
1,873,857
Members
97,598
Latest member
AK Flowers
Top