jarl Posted October 23, 2011 Share Posted October 23, 2011 I have noticed a little white cloud behind my car, on which I recently installed a 2.2 with ~90K miles. I blamed it on the cold weather, but while waiting at a red light this week I realized most other cars were not producing anything similar Today (very cold) I asked my wife to start the car while I played close attention to the exhaust. When she started the engine, there wasn't any significant amount of white smoke. Then I asked her to bring the engine to 3K RPM, and then I saw the smoke coming out. It didn't smell like coolant at all (no sweet smell or anything like that), but rather like gas... lots of it. The EJ22 came from a car that was totaled several years ago so I don't know much about it's history. My question is: can the excess fuel create this white cloud somehow, or should I assume a head gasket is blown? How can I diagnose this? BTW: the check engine light is on, with a code about the oxygen sensor circuit being bad, so I assume this is the cause of the excess fuel. Is it a fair assumption? Quote Link to comment Share on other sites More sharing options...
bstone Posted October 23, 2011 Share Posted October 23, 2011 A bad O2 sensor will murder your gas mileage. Fix it! Get a Subaru sensor, cause the aftermarkets don't work well. Quote Link to comment Share on other sites More sharing options...
jarl Posted October 23, 2011 Author Share Posted October 23, 2011 That's the weird part: the code is for a "bad O2 sensor circuit", not for a bad O2 sensor. From what I have found, this means the sensor's heater is not working as it's supposed to, but the O2 sensor is producing a "legal" output. This seems to be backed by the fact the gas mileage is not particularly bad -I think-. I'm more concerned with the catalytic converter melting or something like that... Now back to our normal programming: white smoke Quote Link to comment Share on other sites More sharing options...
bstone Posted October 23, 2011 Share Posted October 23, 2011 That's the weird part: the code is for a "bad O2 sensor circuit", not for a bad O2 sensor. From what I have found, this means the sensor's heater is not working as it's supposed to, but the O2 sensor is producing a "legal" output. This seems to be backed by the fact the gas mileage is not particularly bad -I think-. I'm more concerned with the catalytic converter melting or something like that... Now back to our normal programming: white smoke I got the same code, circuit error, when the O2 sensor had snapped in half due to driving over a huge snow mound. Replaced with new OE sensor and all is lovely now. Quote Link to comment Share on other sites More sharing options...
NorthernAQS Posted October 23, 2011 Share Posted October 23, 2011 Are you certain that it isn't just condensation/fog that you're seeing? Not all other vehicles will have the same amount in their exhaust depending on the temperature of their particular exhaust components at that particular time. Smoke will hang in the air and diffuse by dilution, regular exhaust condensation will dissapate when the cloud of condensation equalizes with the temperature of the surrounding air at the dew point. If you have smoke coming out of your exhaust, it will happen regardless of the outdoor temperature. Quote Link to comment Share on other sites More sharing options...
john40iowa Posted October 23, 2011 Share Posted October 23, 2011 I got the same code, circuit error, when the O2 sensor had snapped in half due to driving over a huge snow mound. Replaced with new OE sensor and all is lovely now. How are these (when in-tact) to remove? Any special tools? Thanks for any pointers. Quote Link to comment Share on other sites More sharing options...
davebugs Posted October 23, 2011 Share Posted October 23, 2011 7/8 srwnch or special sockets (I kinda like the box end/open wrench combo most of the time. Soak it down good, have patience - and a hammer for the wrench. Quote Link to comment Share on other sites More sharing options...
ocei77 Posted October 24, 2011 Share Posted October 24, 2011 To add: Let the car idle a few minutes to warm it up. Makes it easier. If the cat is very old as a precaution I would hold the bung with one wrench while turning the O2 with another. I have had an O2 bung rip completely out while trying to remove the sensor! Bosch(the originators of O2 sensors) are a good replacement,also. O. Quote Link to comment Share on other sites More sharing options...
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