Possibly a bad maf

[MNBoxster]

Hi,

I mentioned this in another thread, but start by reading your plugs. This is a diagnostic which has all but been forgotten on this day of OBDII cars where people rely more on scanners, but is still a very valid way of discovering what's going on directly inside the cylinder.

As mentioned, the codes you're getting will often not point to a particular problem. A fueling issue or bad MAF will manifest themselves in conditions which other sensors detect or cannot account for and so those codes are thrown instead.

Aside from fuel and air issues, I think there's a distinct possibility of a vacuum leak somewhere as well.

But, as I said, read the plugs. Whitish-gray indicates a lean A/F mix, Tobacco Brown is a proper stoichiometric mix and Black would indicate a rich mix. Go from there. Hope this helps...

Happy Motoring!... Jim'99

[ohioboxster]

Originally Posted by MNBoxster

Hi,

I mentioned this in another thread, but start by reading your plugs. This is a diagnostic which has all but been forgotten on this day of OBDII cars where people rely more on scanners, but is still a very valid way of discovering what's going on directly inside the cylinder.

As mentioned, the codes you're getting will often not point to a particular problem. A fueling issue or bad MAF will manifest themselves in conditions which other sensors detect or cannot account for and so those codes are thrown instead.

Aside from fuel and air issues, I think there's a distinct possibility of a vacuum leak somewhere as well.

But, as I said, read the plugs. Whitish-gray indicates a lean A/F mix, Tobacco Brown is a proper stoichiometric mix and Black would indicate a rich mix. Go from there. Hope this helps...

Happy Motoring!... Jim'99

Well here it is can you see it good enough?

[MNBoxster]

Originally Posted by ohioboxster

Well here it is can you see it good enough?

Hi,

Not the clearest pic, but the plugs look OK. This leads me to think vacuum leak, because whether it was fuel or MAF, either would affect A/F Mix, which by your plugs is good...

Happy Motoring!... Jim'99

[ohioboxster]

Yes, I felt the plugs looked good as well. Im pretty confident its not a vacuum leak I checked for vacuum leaks about a dozen times, the converters dont turn cherry red if the car sits and idles to temp and beyond finally the problem is only at cold start up. Its very strange and seems odd that after resetting the ECU the problem seemed to go away on the next cold start up and the stumble is far less than before resetting ecu. I ordered an Actron CP9135 so I can check which codes its throwing now. Considering ordering an LM-1, data logging software and doing a street tune. Need to check and see which is more cost effective between dyno shop tune or buying all the stuff myself.