I have a 2005 Saturn ion..feel like I am getting run around at JD Byrider. I have been having problems with poor ignition. Engine light on . P0030,P0135 and P0304. They just keep wanting to replace O2 sensors. Can you help?

SOURCE: P0155 & P0135

O2 sensors are tricky. sometimes like anything else they fail. many times though the exhaust mixture they encounter is out of their range and that shows up as a failure.since you seem to have no other problems , I would go ahead and change them, but don't be disappointed if the code shows up again (at least you know it's not the sensors.) I don't like using the process of elimination when doing repairs but sometimes you must.

SOURCE: i have my check engine light on and a p0031 error

On toyotas this is almost always a failed o2 period. Take it somewhere and have it put in. On v6's it is not that easy to get to.

SOURCE: Where is bank1 sensor 1 (O2 sensor) of 2003 Mitsubishi Eclipse

if its a 4 cylinder it will the 02 sensor closest or if not in the exhaust manifold

PAUL MC G

• 1280 Answers
• Posted on Feb 08, 2011

SOURCE: i have five codes P2237

P2237 P2196 P2271 P0030 P0171

These are all O2 sensor trouble codes, except P0171 which is a fuel trim code,

You have a bad 02 sensor - up stream - Bank 1 Sensor 1.

Replace it, then road test. The engine computer has a 'default' fuel trim it uses when an O2 sensor fails so it can protect the catalytic converter. If this hasn't been going on too long, good chance simply replacing the O2 sensor will remedy your problem.

SOURCE: I have a 97 wrangler

Something odd about what you posted. An engine that is running lean shouldn't be using a lot of fuel. Lean is when there isn't enough fuel going into the engine. Two other sensors that regulate fuel flow are the map sensor and throttle position sensor. Temp sensor generally would cause a rich condition but I'd test that too. Be sure to check for vacuum leaks at the manifold and lines as well as fittings... A vacuum leak will give the O2 sensor a lean reading...seeing that, the computer will try to compensate by adding fuel. Clearing codes can change the way it's running but as soon as the computer runs through it's internal diagnostics it will turn the light back on if there is a problem.