Hi all,

I recently discovered something weird: when I hooked up my car on the obd2 at the dealer I got two messages: p1646 & p1647 heated o2 sensor interrupted/short circuit (translated from Dutch scanner). I have no warning lights on the dashboard, although I think I have a crazy high fuel consumption (when I fill up the tank the dash indicator reads +-300km). Is it plausible that both sensors fail at same time and why don’t I get a warning message?

curious if anyone experienced something similar before i buy new sensors.

btw i can’t check anything at home with obd2.. my reader worked on my ‘98 xk8 but not in my xj8 🤔

 

Were they pending codes? Those will show on a scanner before the CEL comes on.

 

Im not sure, i think pending because there is also the code for the knock sensor that comes up on the cel every once in a wile (new knock sensor ordered).

still, it would be a very plausible explanation for the extreme high full consumption, especially sinds this where the only codes…

 

Fuel remaining always starts from low value after fill up. It will go up after you start driving. Atleast mine does. It starts go up somewhere like 440km. What does short and long fuel trims look like when driving ?

 

Sounds like you need new O2 sensors, upstream, both sides. But maybe you also have very dirty injectors that are spitting instead of spraying: clean the throttle bore, plate, MAF sensor; check tube from air filter to throttle body for leaks; run a can or two of a very good fuel system cleaner through a tank of highest test gas available; reset the OBDII to clear codes. Drive it; run it until you get a P1000 (test ready) and see if the 1646/7 codes have stayed off. If not, get new sensors installed (left bank is a bitch to get to).

 

Oké, I changed both o2 sensors and cleaned a very dirty maf sensor (breather pipe was blocked so fixed that also). Yesterday took the car for a long drive and hit 670km range!!!!🥳

more good news: got the obd2 Also working. Bad news is I don’t know if the original o2 sensors where bad or the new (second hand) ones, because i stil get the p1646, p1647 and p1111 as pending fault… any ideas?

 

Your post was automatically locked for moderation. The reason is using multiple emoji's. More than 2 and the thread is locked. I've removed them and unlocked the thread.

Graham