95 Neon running rich

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Mike - 14 Oct 2004 20:02 GMT

Any ideas how to resolved a 95 Neon SOHC 2.0l engine that is running
rich?
I have changed the plugs, cleaned the throtle body, and even installed
a cold air intake (intake was more to remove the mess of tubing, air
box and baffle attached to the air box).
If this was a carburator, the issue would be resolved, but because
everything is controlled by the ECU, I really do not know how to
resolve this issue.

Mike
mlawrenc(at)rcc.on.ca

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deadbeat - 14 Oct 2004 20:44 GMT

My 97 was running rich also. I did the same things, with the exception of
adding a cold air intake. I solved it by getting a new O2 sensor. I was
getting about 14 mpg, and changing the O2 immediately changed my gas mileage
for the better.

> Any ideas how to resolved a 95 Neon SOHC 2.0l engine that is running
> rich?
[quoted text clipped - 7 lines]
> Mike
> mlawrenc(at)rcc.on.ca

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maxpower - 13 Oct 2004 21:51 GMT

a faulty sensor will cause rich problems, map, 02, , have the pcm scanned
for possible fault codes

> My 97 was running rich also. I did the same things, with the exception of
> adding a cold air intake. I solved it by getting a new O2 sensor. I was
[quoted text clipped - 11 lines]
> > Mike
> > mlawrenc(at)rcc.on.ca

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Bill 2 - 15 Oct 2004 03:56 GMT

> a faulty sensor will cause rich problems, map, 02, , have the pcm scanned
> for possible fault codes

Or do a ON-OFF-ON-OFF-ON and record the flashes of the engine light.

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Daniel J. Stern - 14 Oct 2004 22:07 GMT

> Any ideas how to resolved a 95 Neon SOHC 2.0l engine that is running
> rich?

You don't do yourself any favors by putting in a "cold air intake". That
"mess of tubing, air box and baffle" needs to be there; put it back. With
your Ricky Racer, Jr. "cold air intake", fuel economy will suffer,
emissions and engine wear (via oil contamination) will increase.

> If this was a carburator, the issue would be resolved, but because
> everything is controlled by the ECU, I really do not know how to
> resolve this issue.

Same as always: Proper diagnosis and targeted repair. Your rich running
could be caused by a number of rather minor and inexpensive faults, but
guessing and throwing parts at it is the wrong way to do it.

Start by checking the codes.

To check the computer codes:

With the engine off, switch the ignition key on-off-on-off-on,
leaving it "ON". Do not
go to "start", just "on" during this procedure.

Watch the "Check Engine" or "Power Loss" light. It will turn on, then go
off, then will begin to flash-out any trouble codes that have been stored.
For instance, if it flashes:

flash <pause> flash flash
<long pause>
flash flash flash <pause> flash flash flash flash flash
<long pause>
flash flash flash flash flash <pause> flash flash flash flash flash

Then you have a 12 (one flash followed by two) a 35 (three and five) and a
55 (five and five). 55 means "end of codes" or, if by itself, "No codes
stored. Check the codes and report what you find.

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Mike - 15 Oct 2004 12:47 GMT

Throwing parts at it? Spark plugs are sometimes the simplest fault,
and cost $4.50CND for all four and take me about 10 mins tops to
change.
AS for the cold air intake, I will not argue with you on that one. I
know under almost every application, an CAI has been known to add a
little without affecting mileage or life of engine. (The down side is
noise.) But like I said, I will not argue with you on it as not all
add-ons work on every application. Prime example, throtle body
spacers, I done not believe they will do anything, but others beleive
it does.
Now, to the engine codes. The only codes I had when I checked it a few
months ago was A/C clutch sensor. I never use the A/C, so this is no
big issue.
I think I will take a closer look at the MAP and O2 sensors as
mentioned in one of the other postings. There has not been any error
codes displayed regarding then, but I will have then checked when I
bring the car into my neighbour's shops this following week.
Mike

> > Any ideas how to resolved a 95 Neon SOHC 2.0l engine that is running
> > rich?
[quoted text clipped - 33 lines]
> 55 (five and five). 55 means "end of codes" or, if by itself, "No codes
> stored. Check the codes and report what you find.

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Daniel J. Stern - 15 Oct 2004 20:45 GMT

> Now, to the engine codes. The only codes I had when I checked it a few
> months ago was A/C clutch sensor. I never use the A/C, so this is no
> big issue.

OK, but I have to assume you would've posted "95 Neon running rich" a few
months ago had the problem been there, so why don't you check the codes
*again* and let us know what you find *now*?

> but I will have then checked when I bring the car into my neighbour's
> shops this following week.

You don't seem like a very good listener.

> > To check the computer codes:
> >
[quoted text clipped - 15 lines]
> > 55 (five and five). 55 means "end of codes" or, if by itself, "No codes
> > stored. Check the codes and report what you find.

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