O2 sensors and egr valve
I have a 88 base beretta I am having bad gas mileage. I have a 2.0 4 cylinder. Wanted to know if the ecm should pick up o2 sensor if unhooked. My ecm is picking up trottle control and map sensor but not o2. Should ecm pick it up or do you have to drive car to get message. I also think my egr is not working correctly. The repair book said that the engine will stall if you push in the egr diaphram while running mine doesn't.
REPLACE IT WHEN POSSIBLE
If the engine doesn't stall when the EGR diaphram is opened, the intake is either coked up so the EGR passages are blocked, or the computer has learned a much higher IAC (idle air control) count, and has adapted to run with a leaking EGR valve (unlikely, but possible). If the O2 sensor is unhooked--the computer won't respond to O2 sensor data.
Would first try basic mantienace items first. Plugs, wires things of that nature. It is possible buildup of carbon from years neglect. Wouldnt be wise to unplug o2 sensor becaues thats what makes fuel calculations, and you would get even worse milage. Also check air pressure in your tires and make sure there at specs. Your could have the engine rebuilt but for that year/car its not realy worth the money and the time.
Thank you for helping me. I found out that my intake on block was completely blocked. Once cleaned working well. I am getting about 28 miles to gallon. That seems low to me but we got 17" low profile tire and that could be messing up the computer caluations. Sorry for not reponding back life's been busy.
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