Engine light keeps coming on indicated oxygen senors not working properly, replaced them 3 times and engine still comes back on after a week of driving. It is 2004 liberty with 148,000 miles.
anyone else having this problem and if so what did you do to resolve it.
why would they do this Tom? completely entombed in calcium deposits? burned down to the marrow with rich exhaust?
What was your mode of failure RCDunlop? sensor stopped emitting signal because the signal was blocked or because the sensor was burned away?
It was a mechanic that worked on it and replaced the sensors. He told me the next thing would be the computer board. Does that sound right?
...not really, the the reason the sensors are failing should be the area of concern. The ECU is probably faithfully doing it's job based on the data it's been given...should start looking for a vacuum leak, perhaps from/to devices such as the EGR fuel pressure regulator, evaporative canister vacuum and many places...personally would replace all vacuum lines with silicone rubber (the kind BMW uses) summit racing is one supplier, because butyl rubber is notorious for splitting, swelling and not keepin' it's end of the deal up~
...always get your parts back...this way we know if it's really been replaced...my mother had this problem with her '73 gremlin and was charged for a new starter~many hours of jurisprudence for something that was small peanuts~
got a propane torch? wave it over all the vacuum connections [unlit, of course] and note a change in rpm's----that's what should be replaced....really haven't given the benefit of the doubt to Jeep, perhaps they started making their vacuum hoses from the good stuff...test and find out~
http://www.amazon.com/Spectre-28906-Silicone-Vacuum- Hose/dp/B00062ZRI2
shipping is a little chompy on that, maybe you could find a supplier on your own at a 'custom shop' or even the BMW dealership~ think autozone has them~
http://www.oreillyauto.com/site/c/detail/GAT0/27075.oap?pt=N0890--- oreilly $8.99 plus shipping...only fleshy colored~~:(
or get a mechanic that can read codes, what's the trim value while running?
the O2 sensor actually gets eaten away (the expensive platinum part) have taken them off to find a hole where a probe belonged but still made with the micro-volt signal okay yet~
am leery of those that want to replace the ECU...because never have I seen where the ECU is at fault...it is ALWAYS proper grounding to the unit~
wirebrush the main ground connection [1/0 cable to frame] connection as dis- similar metals will evaporate and leave corrosion behind....coarse wirebrush this stuff all away till exposed metal...this will be your coarse to get the thing to behave properly~
I have replaced my O2 sensor three times and gas cap and check engine light has stayed on now it blinks at me and cuts my gas out for a minute mainly on hills then lunges me forward. However computer reads a random misfire replaced could and spark plugs. Terrible on brakes and bearings too. Any advice is helpful. I truley believe it's in the vacuume will post results.
Spark plugs fixed it for me
