1993 GMC Sonoma code 45, 4.3 vin W.
Question:
A quick history first. The truck was caught in a flash flood last summer, did all the usual work…. filters, fluids, and such. New EGR valve and evap. canister. New O2 sensor before the flood. Only gets about 15 mpg. Runs as good as it ever did. The computer was NOT under water, the engine only to the top of the heads. Found water in ONLY two cylinders. My theory…backed up through exhaust. Code 45 came up once before, replaced EGR, needed it anyway. My thoughts are that the O2 sensor is coated with dirt, and not working correctly, OR the catalytic converter is partially plugged with dirt, OR a combination of both. Ideas? Maybe just replace the O2 sensor? Please reply here, borrowing a computer from a friend. TIA, RJ IN WV
Response:
If you look at the thread you started yesterday you’ll see that I posted a reply. I’m not gonna repeat it again… – Hide quoted text — Show quoted text – > A quick history first. The truck was caught in a flash flood last summer, > did all the usual work…. filters, fluids, and such. New EGR valve and > evap. canister. New O2 sensor before the flood. Only gets about 15 mpg. > Runs as > good as it ever did. > The computer was NOT under water, the engine only to the top of the heads. > Found water in ONLY two cylinders. My theory…backed up through exhaust. > Code 45 came up once before, replaced EGR, needed it anyway. > My thoughts are that the O2 sensor is coated with dirt, and not working > correctly, OR the catalytic converter is partially plugged with dirt, OR a > combination of both. > Ideas? Maybe just replace the O2 sensor? > Please reply here, borrowing a computer from a friend. > TIA, > RJ IN WV
– Reach me by ICQ. My ICQ# is 8023912 or, * Page me online through my Personal Communication Center: http://wwp.icq.com/8023912 (go there and try it!) or, * You may visit my Personal ICQ Homepage: http://members.icq.com/8023912 Download ICQ at http://www.icq.com/download/ For adding similar signatures to your e-mail go to: http://www.icq.com/email/emailsig.html
Response:
Thanks fellas! I never even thought about that connector, missed it during the flood cleaning too. I also noticed it only sets the trouble code on wet days. I hope that is all it is. $400 ouch!!! Thanks again! RJ IN WV
– Hide quoted text — Show quoted text -> A code 45 is set for a rich condition. You could have a water problem with your > HO2S if it is a HEATED O2 sensor, you can tell by the number of wires to the > sensor itself, if you have more than one wire (typically two or three) then the > O2 is heated. With a heated O2 you should check the connectors for signs of > corrosion or tracking between the teminals. If there are no signs of > cross-feeding then an O2 is not a likely culprit most O2 sensors Either fail to > work at all (setting a Code 13) or they fail lean (setting a Code 44). (A drop > of water can cause cross-feeding due to the fact that O2’s use less than 1 volt > as it’s signal, and the heater is fed B+). The next thing that could cause your > problem is a worn CPI Injector. If your CPI is worn(which is a typical problem > with the early CPI motors,’91-’93) you may have a sulfur smell when driving in > city or stop a go traffic, the idle may start to surge after a 10 mile drive and > then let the truck idle for an extended priod of time ie: long line at > McDonalds drive thru, and poor gas mileage. Other than those few simptoms the > truck will run fine until the converter can’t handle the load any longer. If > you have access to a scan tool a Block Learn (Long term fuel trim) value below > 110 is indicative of a bad Injector. Hope this helps (Hope it is not your > Injector, part cost is over $400.00 last I heard) ED > A quick history first. The truck was caught in a flash flood last summer, > did all the usual work…. filters, fluids, and such. New EGR valve. and > canister. New O2 sensor before the flood. Only gets about 15 mpg. Runs as > good as it ever did. > The computer was NOT under water, the engine only to the top of the heads. > Found water in ONLY two cylinders. My theory…backed up through exhaust. > Code 45 came up once before, replaced EGR, needed it anyway. > My thoughts are that the O2 sensor is coated with dirt, and not working > correctly, OR the catalytic converter is partially plugged with dirt, OR a > combination of both. > Anything I might have missed? > Please reply here, borrowing a computer from a friend. > TIA, > RJ IN WV
Response:
A code 45 is set for a rich condition. You could have a water problem with your HO2S if it is a HEATED O2 sensor, you can tell by the number of wires to the sensor itself, if you have more than one wire (typically two or three) then the O2 is heated. With a heated O2 you should check the connectors for signs of corrosion or tracking between the teminals. If there are no signs of cross-feeding then an O2 is not a likely culprit most O2 sensors Either fail to work at all (setting a Code 13) or they fail lean (setting a Code 44). (A drop of water can cause cross-feeding due to the fact that O2’s use less than 1 volt as it’s signal, and the heater is fed B+). The next thing that could cause your problem is a worn CPI Injector. If your CPI is worn(which is a typical problem with the early CPI motors,’91-’93) you may have a sulfur smell when driving in city or stop a go traffic, the idle may start to surge after a 10 mile drive and then let the truck idle for an extended priod of time ie: long line at McDonalds drive thru, and poor gas mileage. Other than those few simptoms the truck will run fine until the converter can’t handle the load any longer. If you have access to a scan tool a Block Learn (Long term fuel trim) value below 110 is indicative of a bad Injector. Hope this helps (Hope it is not your Injector, part cost is over $400.00 last I heard) ED – Hide quoted text — Show quoted text – > A quick history first. The truck was caught in a flash flood last summer, > did all the usual work…. filters, fluids, and such. New EGR valve. and > canister. New O2 sensor before the flood. Only gets about 15 mpg. Runs as > good as it ever did. > The computer was NOT under water, the engine only to the top of the heads. > Found water in ONLY two cylinders. My theory…backed up through exhaust. > Code 45 came up once before, replaced EGR, needed it anyway. > My thoughts are that the O2 sensor is coated with dirt, and not working > correctly, OR the catalytic converter is partially plugged with dirt, OR a > combination of both. > Anything I might have missed? > Please reply here, borrowing a computer from a friend. > TIA, > RJ IN WV
Response:
A quick history first. The truck was caught in a flash flood last summer, did all the usual work…. filters, fluids, and such. New EGR valve. and canister. New O2 sensor before the flood. Only gets about 15 mpg. Runs as good as it ever did. The computer was NOT under water, the engine only to the top of the heads. Found water in ONLY two cylinders. My theory…backed up through exhaust. Code 45 came up once before, replaced EGR, needed it anyway. My thoughts are that the O2 sensor is coated with dirt, and not working correctly, OR the catalytic converter is partially plugged with dirt, OR a combination of both. Anything I might have missed? Please reply here, borrowing a computer from a friend. TIA, RJ IN WV
Response:
Check the EVAP canister for presence of fuel. Replace the O2 sensor. This is according to my Haynes manual… – Hide quoted text — Show quoted text – > A quick history first. The truck was caught in a flash flood last summer, > did all the usual work…. filters, fluids, and such. New EGR valve. and > canister. New O2 sensor before the flood. Only gets about 15 mpg. Runs as > good as it ever did. > The computer was NOT under water, the engine only to the top of the heads. > Found water in ONLY two cylinders. My theory…backed up through exhaust. > Code 45 came up once before, replaced EGR, needed it anyway. > My thoughts are that the O2 sensor is coated with dirt, and not working > correctly, OR the catalytic converter is partially plugged with dirt, OR a > combination of both. > Anything I might have missed? > Please reply here, borrowing a computer from a friend. > TIA, > RJ IN WV
– Reach me by ICQ. My ICQ# is 8023912 or, * Page me online through my Personal Communication Center: http://wwp.icq.com/8023912 (go there and try it!) or, * You may visit my Personal ICQ Homepage: http://members.icq.com/8023912 Download ICQ at http://www.icq.com/download/ For adding similar signatures to your e-mail go to: http://www.icq.com/email/emailsig.html
