Running rich

[Craig A Updegrove]

I got a 98 Acura Integra. Got an engine oil leak somewhere on right side(passenger side. No oil in radiator, No coolant in oil.I cleaned that side. I am waiting to see where it is leaking from. I also replaced valve cover gasket(Acura OEM)
I noticed Gas smell form the tail pipe while running. MPG Has decreased by about 4 MPG. what could be causing these things

1998 Acura Integra LS Sedan

Topic

[college man]

Actually if your smelling gas your running rich to
much fuel.start with your ignition components.
no cel on?

https://www.ericthecarguy.com/faq/solving-automotive-performance-issues

[Bill]

If it has high mileage and the O2 has never been changed it’s possible it’s getting tired. Most cars in those years the sensor had to be almost dead to turn on the MIL light.
You could verify it’s operation with a scan tool that reads data.

[dreamer2355]

When did you last do a tune up?

[Pat]

Bad gas smell in exhaust usually is a rich condition. ” i believe this was stated above” If you are just looking for stuff you can try on the cheap, I recommend back probing your M.A.F. to make sure the voltage is correct, and also cleaning the MAF. You can also test your O2 Sensors by grounding the V meter to the “nut” on the side,pinch the ground probe in between a vice and the metal housing or nut of the O2 snesor, and probing the feedback wire that communicates with the ECM. on a 1 or 2 wire system this is easy to do. After connecting the Volt meter heat your O2 sensor tip with a propane torch, you should get up to @ least 1V DC when you remove the heat from it, the voltage should start dropping pretty much Immediately. That is a couple of the common problems for a rich condition. The topic mentioned Lean, I must have missed something somewhere, because without a CEL saying lean condition, a bad gas smell is usually a rich condition. However if the MAF or O2 sensor is malfunctioning, it can show lean but be running rich from the computer trying to over compensate.
the only common thing in this equation is a Volt meter, (which you can pic up on the cheap from about 9 dollars to 20 dollars, or some MAF sensor cleaner. pretty cheap way of checking it out without actually just throwing parts at it.

P.S. If you have a rough idle I would check for a Vacuum leak also.

Hope I helped you.
Have a nice day.

PAT

[Craig A Updegrove]

As far as i am aware the Acura Integra doesn’t have a MAP it does have an MAF. Do they do the same thing? and which O2 sensor should I check the one before the car or after how do I check them? tune up was 6 months ago(plugs and wires, filters,fluids rotor and cap)front brakes also. I have what sounds like I need front wheel bearings. Can I do one at a time. how do I tell which is worse?

Would that cause decrease in MPG?

[Craig A Updegrove]

wheels do not shake only hear it in slow turns.

[Craig A Updegrove]

No CEL light on

[Craig A Updegrove]

I also replaced both calipers on the front wheels Left and right.

[Craig A Updegrove]

Lasat tune up 6 months ago

[Bill]

The O2 sensor in front of the converter is the one to look at.

[Craig A Updegrove]

How do I go about checking it. I have meter and scanner to read codes. It would happen to be the expensive one.

[Craig A Updegrove]

would the fuel pressure regulator have anything to the decreasing MPG.
How could I check that

[Bill]

You would need a fuel pressure gauge to check the fuel pressure regulator. With the vacuum line disconnected the pressure should rise and fall again with the vacuum hose connected. You could check the O2 sensor with a volt meter but an scope graph is the best way. Since those tools are expensive I would just replace the sensor.

[Craig A Updegrove]

Thanks for every bodies input I am going to try the upstream O2 sensor. see what happens then

[Author]

Replies