Argonaut

Today my check engine lite came on. Using my XCal2 I found two DTCs: PO155 and PO161. Doing an online search yielding incredibly little useful information about these. I was able to learn that both have to do with O2 sensor heater circuit malfunction. The car only has 1500 miles on it. It does have a CAI and custom tune but I don't know that these have anything to do with the problem.

Does anyone have any advice...other than take it to the dealer?

Also - If anyone knows more about DTCs in general and a good source of information for diagnosing what they mean and what to do about them...I'd appreaciate it if you passed it along.

Thanks.

banka87

Flash the thing to stock, put the stock air box back on and see what happens. Problem persists, take to dealer.

Argonaut

Thanks - thats pretty good advice. Anyone else out there with a comment?

banka87

My comments not good enough for you?

haha j/k

Derf00

Both errors relate to O2 heater circuit malfunctions. All 02 sensors since the mid-90's have heating elements built into them. This helps them reach operating temp much faster than the old way of just letting the exhaust heat them up.

Get under your car and check to make sure your rear 2 sensors are plugged in all the way or that the wires haven't been damaged.

grampa_stang

Here's the complete guide:

http://www.cherod.com/mustang/Docs/DTC_Codes.pdf