Gas mileage is bad, black tailpipe. O2 sensor light still comes off/on after replacing O2 sensor. Ticking noise passenger side of engine. 42000 miles.
Bad gas mileage - front O2 sensor light was replaced, ticking passenger side eng on 2005 Dodge Ram 1500
There are actually two oxygen sensors on your vehicle and it is possible the one that was not replaced was not the one setting the code or they are both defective. As well, when replacing an oxygen sensor, we always recommend installing an oxygen sensor that has the original equipment connector. Not the universal fit style. Those nearly always give problems. Either way, a faulty oxygen sensor can cause poor fuel economy and possibly black smoke (excessive carbon) out of the tailpipe. As far as the ticking noise goes, I suspect that is a different issue altogether, possible lifter issue? What I would recommend is having the vehicle diagnosed/inspected to find out where these issues are coming from. Hopefully that helps.
Thank you this makes sense regarding O2 sensors. Somebody just told me that 2002 - 2005 are famous for the exhaust manifold bolts breaking or rusting off and that the ticking is a common problem on these models requiring new bolts and gasket, possibly bolt extraction, haven't checked yet (work) but will ASAP.
Yes. Exhaust manifold and/or gaskets are common for those 5.7 Hemis. Does the pitch of the tick change (get louder or quieter as the vehicle warms up)? If it does, through thermal expansion and contraction (metals/gaskets flexing do to variances in temperatures) the pitch will change. That may help isolate the issue.
Thank you again, that is an excellent point (thermal expansion) and it will make diagnosis easier.