[huskybruiserjr]

all the mods are in my sig
id really like to get more mpg
engine check light is on
read codes and it doesnt throw any codes
im thinking o2 sensor or maf
any help would be appreciated

 

[hEaT]

How did you check codes? For a CEL, you'll need a code reader. The odometer trick won't show it.

That would be the first step before you start replacing anything, but the primary o2 is a good guess.

 

[huskybruiserjr]

i have a sct xcal 3

 

[Liquid_02_ZX3]

Has it always gotten 19mpg?
Any other problems when driving?
When did the check engine light kick on?
How long has the check engine light been on?
Get the check engine light scanned? a real scanner will show pending codes.

 

[huskybruiserjr]

gotten it scanned multiple times
check engine light has been on for a while
only other problem when driving is when it idles for too long the engine rpms start bouncing a little

 

[Liquid_02_ZX3]

So your check engine light is on, and there is no codes? And you have cleared the non existent codes and the light remains on.

 

[G-forces]

Bad gas mileage could be the top O2, or dirty injectors, or partially clogged cat. Variable idle could be dirty MAFS, sticky IAC, or leaky EGR valve (if it was a worse leak, the idle would hang high). Clean everything and then have someone datalog it.

 

[huskybruiserjr]

when i clear the codes it goes off for maybe a minute
not a clogged cat checked that before exhaust was put on
hopefully its the top o2

 

[Liquid_02_ZX3]

I'm a master certified technician that specializes in driveability problems such as these, I have never seen a CEL illuminated while the computer gives you no information explaining any code/fault information. My guess would be the primary 02 sensor. You said your cat was good when the exhaust was put on. Depending on how long you have been running rich your cat may now be gone. You can overheat and ruin your catalyst in an hour, it doesn't take long. I hate having people throw parts at cars without knowing what faults are saved in the PCM.

 

[FordFociSHO]

Faulty Cam Position Sensor will throw a light almost immediately, I think. Generic OBD won't show a code for it either. Not sure if the SCT scans generic or Ford specific, I'd guess generic.

 

[Nickgt40]

I'm not sure if this would throw a code, but possibly check to make sure your thermostat is working correctly. If the engine is running either too hot or too cold that could hurt your mpg.

 

[Johnny_P]

gas cap on tight?

 

[zx3r_type]

It may be your IMRC throwing a code. Most cheap code readers cannot read that code. If I can make it to the meet on Friday, I will bring my Snap-On Modis with me, and try to pull it up.

 

[focusownerskid]

I'd like everybody to stop for a second and wait for the OP to answer this question;

When the CEL is ON, BEFORE you clear it. WHAT is the code that is present?

Gonna need that one answered before useful information can be given.

- Drew

 

[Liquid_02_ZX3]

I'd like everybody to stop for a second and wait for the OP to answer this question;

When the CEL is ON, BEFORE you clear it. WHAT is the code that is present?

Gonna need that one answered before useful information can be given.

- Drew

Absolutely but his flasher isn't pulling up his codes, this is internet diagnosis soup at its best.

 

[huskybruiserjr]

exactly my sct scanner shows no codes
ill be at the g2g on the 5th in madison and at the massive meet later that night

 

[Liquid_02_ZX3]

It wouldn't hurt to try the autozone free scan.

 

[huskybruiserjr]

probably doing that tonight after work

 

[zx3r_type]

It wouldn't hurt to try the autozone free scan.

But they use one of those cheap generic scanners too, that can only read P0 codes. If it is a P1 or up code that comes up, the generic reader will not read it, but can still clear it.

 

[huskybruiserjr]

im heading down to ford to have them scan it in about 5 mins