JPat

Hey guys my 05 SE 1.7 has been surging. I unplugged the first oxygen sensor and it runs reapy good

What happens when i unplugged it? did the car go into some limp mode, or like a "Base tune" where it runs good but not perfectly?

toyomatt84

iTrader: (1)

Its now running in an Open Loop fuel map, because its not pulling data from the Oxygen Sensor. You'll see a decrease in fuel economy, increase wear on the engine, and a Check Engine Light.

JPat

Iam okay with everything but wear on the motor. Its got 250000 already. With the original sensor and the aftermarker sensor it drives like your pushing the fuel pedal up and down every second or so while your driving.

I need a honda sensor. 300$ yuck

toyomatt84

iTrader: (1)

Is it an LX SE? If so, have you checked the exhaust manifold for cracks?

JPat

I think so. Its a base model 1.7 non vtec auto, It has a brand new stainless manifold no leaks, altho it did i have leaks and the exhaust helped alot

toyomatt84

iTrader: (1)

So you got rid of the catalytic converter? That could easily be a problem. (Non-VTEC engines have a catalytic converter in the exhaust manifold)

JPat

Yeah but the 1st sensor is before the cat, and the second one just tells us if the cats working. Or so experience has led me to beleive

I put the same exhaust on my si and my old dx without a problem. Only because the stainless header is 85$ with bolts and gaskettes from ebay and the cheapest one around gere is 400$ish

toyomatt84

iTrader: (1)

Without a catalytic converter, you're going to be running super lean or in Open Loop (if you don't run a primary O2 sensor) without some form of either O2 sensor fooler, or running a combination of spark plug fowlers to get the secondary O2 sensor out of the stream. Neither of those conditions is good for your engine.