@michaelscai
Yes, you need the intake gasket before doing the back 3 plugs
It’ll probably be referred to as the plenum gasket
Make sure you tell them you’re just doing plugs, NOT removing the lower manifold
It is possible that one of the larger parts stores has a Felpro plenum gasket in stock
The “catch” is invisible when the connector is installed. The “release” is the little black paddle shaped thing just behind the connector. You want to push the connector in fully, push down on the paddle, and pull straight out. Do not pull anything out before pushing the connector inward.
can i spray wd-40 on it, would that hurt anything?
It would not help, and I wouldn’t recommend it. WD40 is a solvent, and I’m always wary of spraying solvents on plastics.
ok finished the back three plugs, everything went well…for a moment i felt like a mechanic…
at one point i went brain dead and try to scew in the spark plug without first take out the old one, i didnt put too much force on it, just wonder why it wasnt going in…that lasted a min… i hope that didnt damage the platinum tip or anything on the new plug??
took me over two hours but it was fun doing it!
intake manifold removed, didnt change gasket
@michaelscai
Please change the gasket
You’re asking for lean codes
if i visually exam it and no oil leak, do i have to worry about that? I already have check engine light on because catalyc convertor errror for a while…
Delete
@michaelscai
Not all lean codes are in conjunction with a rough idle
Recently, I fixed a truck which ran very well, yet had the check engine light on. The lean code was due to a leak in the intake manifold. Reusing the gasket is asking for trouble in my opinion. It may not seal perfectly again.
One more thing . . . the check engine light is on for the catalytic converter, according to you. All you know is the light is on. You don’t know how many codes . . . or what codes . . . you have.
People that have the light illuminated for a long time should not assume that ONLY the original fault code is present.
In any case, looking at the fuel trims at idle should tell you if you got away with reusing the gasket.
I assume everything is back together.
Can I assume the plenum gasket set was somewhat expensive and/or special order and/or dealer only?
How do I measure fuel trim? I called Mazda dealer for the gasket yesterday it’s only 2 bucks but they didn’t have it in stock.
It runs fine hope no leaks will pull codes from time to time
I agree with Db’s advice on the gaskets. Gaskets take a “set” when installed and should never be reused. Frankly, spark plugs with square shoulders and crushable metal gaskets should not be reused either. Once installed, they’re designed to deform to the irregularities and exact surfaces of the surface they’re compressed against, and they’re not designed to be reused.
Parts stores will generally carry all the common gaskets for most common cars. I’m sure one of the ones in your area will have a replacement gasket.
so i should replace the gasket or can i wait? i dont see any oil leak from the intake manifold edges…
i followed instructuon here this guy didnt change gasket either http://www.bobistheoilguy.com/forums/ubbthreads.php?ubb=showflat&Number=2979127
WOW 3 months later and still trying to do a plug change. Then you seem to want to disregard and argue with the advice given by people who know what they are talking about. Just do the job any way you want, but don’t cry if the results are not as expected, or you end up doing parts of the job (gasket) over again.
easy big fella, i just want to know if i need to replace it right away or can this wait…never said i was an expert in this but I saved bunch money by doing it myself and enjoyed doing it, lots of advices here definitely helped!
You would need a scan tool to measure fuel trim
You’ll probably be fine
But if you have a lean code in the future, it’s most likely the gasket
So the next issue is the catalytic converter?
fixing the catalyc convertor will be a bit over my head, ive been running with that check engine light on for like 40k miles
@michaelscai
Then you’ll just have to live with the check engine light lit permanently
And you’ll also never know if there are other codes besides the P0420 cat code, unless you hook up a scan tool to retrieve codes
May I presume you don’t have to get your car smogged?
@michaelscai
Something just occurred to me, because I just did plugs and the pcv valve on my V6 Camry, this afternoon
It’s got a transverse engine, so I also had to remove the plenum.
Anyways, my rubber plenum gasket was not torn, but it was flat as a board and NOT pliable
I replaced it, because I already had a new gasket in hand.
I’m NOT rubbing anything in. I’m just saying it’s better safe than sorry.