New o2's

[3.4King]

Ok guys got the computer scanned came up both o2's were bad replaced them and a littk before then replaced the iac valve and plugs and wires. Still only getting 15-16 mpg what else can I do to improve mpg? It still throwing codes for o2's as week very frustrating

[thebeewantsboost]

Re: New o2's

if you cleared the code and it's coming back you still have a problem, possibly burnt or shorted wires. a new fuel filter will keep your fuel pressure at the rail high and keep atomization/efficency at its best.

[3.4King]

Re: New o2's

The wires look fine unless I'm missing something? Where is the fuel filter located and any other ideas as to why gas mileage still isn't great? Also starting to think I need a new cat. When I get on it it goes nowhere and it'll slowly clear up and when it finally does it spIts out black smoke

[thebeewantsboost]

Re: New o2's

are you sure its not throwing a code for the cat O2? i believe the fuel filter is on the passenger side in front of the rear tire under the car. those symptoms do seem like a cat

[3.4grapeofwrath]

Re: New o2's

The wires look fine unless I'm missing something? Where is the fuel filter located and any other ideas as to why gas mileage still isn't great? Also starting to think I need a new cat. When I get on it it goes nowhere and it'll slowly clear up and when it finally does it spIts out black smoke

Black smoke indicates a rich fuel mixture. Check your spark plugs to see if they are black with carbon. You might need to replace or clean them. Possible the engine coolant sensor is bad and giving a false reading of being too cold. The rich condition can also build carbon on the O'2s but once you fix the problem that should burn off. If the fuel filter was clogged you would be running lean not rich.

[3.4King]

Re: New o2's

The o2 sensors I pulled out where black as black could be I replaced both o2 uptop I'd there another I'm unaware of?

[thebeewantsboost]

Re: New o2's

the only other is after the cat and not used for afr. is it running better? if it's running like you say, you might have a stuck injector. does it start fine? does the oil smell like gas?

[3.4grapeofwrath]

Re: New o2's

The 3.4 only has two O'2 sensors.

[3.4King]

Re: New o2's

Still a fast idle and strong exhaust smell. Idk what else to do >_<