How do i know if car is running rich?


#1

Hi folks,

I have a scangauge II on my Scion xA. I recently found several complaints on www-odi.nhtsa.dot.gov saying that some xA’s were shipped with improperly gapped spark plugs and causes the engine to run rich, eventually harming components (catalytic converter, etc.). Short of taking the spark plugs out and checking the gap, is there a reading I should be looking at on my ScanGauge that could tell me if the engine is running rich?



Below you will find one of the actual complaints relating to this (please excuse the caps, posting as it appears):

“2006 SCION XA COMES FROM THE FACTORY WITH IMPROPERLY GAPED DENSO SPARK PLUGS THEY ARE GAPED AT 23 THOUSANDTHS THIS CAUSES THE CAR TO RUN RICH CAUSING TONS OF POTENTIAL SENSOR FAILURES. DENSO SPECIFICALLY STATES THAT THEIR PLUGS ARE TO BE GAPED TO 44 THOUSANDTHS WE OWN TWO XA THE SAME YEAR AND BOTH CARS HAD THE SAME PLUGS BOTH WERE GAPED WRONG AND BOTH CARS HAD PLUGS THAT WERE FOULED OUT AT LESS THAN 400 MILES THIS IS A MAJOR PROBLEM THAT NEEDS TO BE CORRECTED SCION ACKNOWLEDGED THE PROBLEM TO ME BUT REFUSED TO REPAIR IT UNDER WARRANTY AND REFUSED TO ISSUE A RECALL THEY DON’T CARE THAT THIS IS A MAJOR PROBLEM EFFECTING CARS AND THE ENVIRONMENT I PULLED THE PLUGS ON A FRIENDS 2004 MODEL AND THEY WERE GAPED IMPROPERLY AS WELL AND HE HAS HAD TO SPEND THOUSANDS REPLACING SENSORS THAT WERE ALL CAUSED BY HIS CAR RUNNING RICH”



ScanGauge digital gauges:

Fuel Economy

Fuel Rate

Battery Voltage

Coolant Temperature

Intake Air Temperature

Engine Speed (RPM)

Vehicle speed (MPH and KM/H)

Manifold Pressure(not available on some vehicles)

Engine Load

Throttle Position

Ignition Timing

Open/Closed Loop



Any help would be appreciated.

elcuc0


#2

If I were staring at “Thousands replacing sensors because spark plugs were gapped incorrectly”, my first action would be to pull out my ratchet, plug socket and $1.29 gauge and then take an hour to make certain my plugs were gapped properly. Most often the simplest procedure makes the most sense.


#3

Why not just pull the plugs and check them? The real test is to read the oxygen sensor readings, but your scangauge doesn’t do it.


#4

You may want to be careful with the information you recieve. It would be very rare for one sensor to go so bad that it ruins an associated sensor. If there is such a major problem in that chain of sensors the engine light would come on and the only way extensive damage can occur is whe the engine light is disregarded. But, the spark plug issue sounds like an issue that should be contested. Unfortuneatley ther are a lot of businesses out there that think people don’t have the time to protest things. It’s that same attitude Bill Clinton was wishing he had: apathy.


#5

“Short of taking the spark plugs out and checking the gap” Why not check them, you have spent more time writing your message than it takes to do the job on most cars. You will know after checking one or two plugs anyway.

In any case I would not jump on those complaints assuming they are both real and apply to your specific car. Verify with the dealer and your owner’s manual what the proper gap really is before proceeding.


#6

Simply replace the plugs with properly gapped ones. The plugs are a flat base with gaskets, and those gaskets once compressed should not be reused.

And use a torque wrench. Sears has a perfectly good beam type for a mere $25.


#7

The illiterate nature of the complaint is a tip-off. It’s also a load of male bovine excrement. Misfiring will cause the “Check Engine” light to come on when it gets bad enough, and ignoring the light is what will eventually lead to damaged sensors, as Beefy Norm pointed out.

If you are concerned, check the plugs.


#8

You should not be relying on a ScanGauge for much of anything; assuming your post is not an effort to sell these things.
(Mr. Louis LaPointe, of acetone fame, is a firm believer in this widget).

I don’t put a lot of faith into many of those complaints on the NHTSA website because those complaints are often made by people who have no idea what the problem is, what caused it, and will surely not admit to being part of the problem themselves. The entire story is not posted, which is usually the norm.

Gapping the plugs too close will cause a misfire, easily fouled plugs, rich running, etc. but if someone has had to spend 1000s of dollars replacing sensors because of rich running then they do not need to be driving anything. This means they’re been motoring around for eons with the CEL illuminated and/or flashing and chose to turn the radio up instead of repairing the fault.
Fix the problem when it occurs and the problematic carryover won’t happen.


#9

I also concur that the post seems fishy. If this were a genuine problem, I have no doubt that Toyota would be all over it. I can get a spark plug for a 1.30 or so, so imagine how cheap Toyota can get them for, plus they’re incredibly easy to change on these cars. This would probably be an extremely cheap recall for them and they generally like doing cheap recalls because it gets people into the service departments where they can sell them other services.

As the other posters have mentioned, if the mixture goes even a little bit rich the oxygen sensor will detect it and turn on the Check Engine Light.


#10

It does sound like a case of the blond leading the blond. Like most such things, there is more mis-information than information…much of it stemming from a lack of knowledge of how things (engines, etc.) operate.


#11

Thanks everyone for your responses. My problem is that I live in a condo, and working on cars is not allowed. I don’t know where I could do this, and being that I have never done this before, it will probably take me a bit longer to do than someone who has done this before on their cars. I don’t want to break anything…

If you live in Maryland (I’m in Silver Spring) can show me how to do this or know of a place place where I could do this, please let me know.

Thanks!
elcuc0