Engine warning light?

[leilanidude]

If you replace the CAT with a test pipe, your secondary O2 sensor will detect a failure of the CAT and vehicle power and fuel mileage will suffer. Unless of course, you also buy a secondary O2 sensor that is "rigged" to send a false signal... Yes, those really do exist.

edit to add: The code is not a diagnosis. It is a way to help you find the problem that caused the code to be set.

[b_a]

quote:

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Originally posted by kalakoa

you may be buying a new CAT convertor

No emissions test in Hawaii, you can just replace the cat with a "test pipe".

Why the heck would you even say something like that? Haven't seen a test pipe since the early '90s, and even then they were illegal.

the CEL could set the vehicle into limp-home mode

Only if certain sensors (eg, the MAF) fail.


But without actually scanning the computer, you won't know, now will you? Mass Air Flow sensor failure would certainly do it, but I got multiple limp home mode failures from a slightly glitchy TPS (Throttle Position Sensor) - fix was to reprogram the computer so it wasn't so finicky about the data (but I made them replace the throttle body under warranty anyway.)

Anybody think the OP will ever come back to provide more info?

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...we are everywhere...

[Johnd]

Get a new gas cap, and ask a part store to check the code and they will even turn off the light for free. Sensors tend to malfunction with rain and condensation. Not having a good seal on the gas cap is usually the problem

jdo

[onrway]

HERE IS THE REST OF THE STORY
First please understand that I am in no way a mechanic.
I have a 2010 Ford Fusion with 6 cylinder engine and about 55,000 miles. two months ago I took it to a reputable shop in Northern Ca. It has a check engine light. I was intending to sell the car and it would have to pass smog test in order to be sold. A check engine light is an automatic fail and they won't even do the smog test. The shop had the car for a month and finally said they had replaced a "CANISTER PURGE VALVE $128.25 and VALVE COVER GASKET $450.00 DETONATION KNOCK SENSOR $60.00 and SOLENOID $60.00" We took the car home and the light came back on after about 80 miles. So they said bring it back. They worked on it some more. They had us come get it again $120.00 parts only with no labor charge and again similar experience. The light came back on so took it back to them. They still have it. When I called, they told me that the cylinder compression is supposed to be at 140 and that the cylinder that had the injector problem is at 100 which is still acceptable. However since it is so much different than the other cylinders that are at 140. It triggers a check engine light. The car runs fine, The only other problem with the car is it has a driver side airbag light which they tell me is caused by a $500.00 sensor under the drivers seat. I was considering bringing it to BI. That is why I asked about the safety inspection.

[Tink]

Too bad they still have it. If it is at the dealership, it is time for a phone call to the district manager at Ford. When you do get it back, invest in a Code reader as suggested, and if the light comes on again, read the code and know what the problem is first hand, and not rely on the repair shop. If they did their job, ALL codes and problem areas would have been noted, and you would not have the run around of maybe it's this, maybe it's that. As far as a cylinder more than 10% different than the rest, it is not acceptable in my mind and change the one injector if it is truly faulty. Swapping the injector to another cylinder and test run would tell you if it is indeed faulty, as the fault would move from say cylinder 4, the original fault location, to say cylinder 5, the "test" cylinder location. Your detonation sensor was picking up this bad cylinder, and may not have needed replacement. It also puts too much strain on the rest of the engine, and more problems will arise within your emmissions system, as well as give you poor gas mileage.
There is also a recall with certain models of Ford product on the airbag, check yours to see if it applies. All these repairs will cost you more here, as well as waiting for parts...

Community begins with Aloha

[Obie]

Low compression can give you all kinds of codes but the problem is actually a mechanical problem.You probably have a bad valve ,maybe broken valve spring.It's not going to get better.

Why did they change the valve cover gasket ? Did it have a big oil leak and did you run it low on oil ?

If you bring it here and it needs a new cylinder head it will cost more here than there.

[onrway]

Thanks for the advise. We were in hopes of selling the car and the proceeds would help pay for our start up In Puna. As is, since it will not pass Smog, I can not sell it as an operable vehicle. Since we are headed for the BI the first of the month, I do not see any since in putting more money into a car we will not be driving. The only other option that I can see is to sell it as a inoperable vehicle. Then someone else can do the work needed and then register it as salvaged. I could also sell it to a junk yard. Too Bad since it is a really nice car. Any suggestions appreciated
Thanks

[Obie]

The airbag light is a definite failure item.Many of the inspection stations don't check it but many do.

[leilanidude]

Federal new car emission warranties have been, since 1972 - 5 years 50,000 miles. This means that any emission related failure is covered to that point, even if the general factory warranty was less than that.

As for your airbag sensor - you can probably get that at any auto parts store for way less and plug it in yourself. get the name/part number from the dealer.

Remember, a code is not a diagnosis. It is starting point on what to check.

[onrway]

Thanks Leilanidude That is good informations. Is that 5-years and or,or 50,000 miles. Either way they are both up now.