1) New MAF reads about 7g/s at idle. Seem correct?

2) MAF reads 5.5 gs ignition on motor off

3) front o2s read .09 to .9 and the cycle all over in between.

4) just added back o2s to my ultragauge. Key on they read .445 each. Once motor warms up they are cycling between .8 and .1 this does not sound good but are the cats toast or just a major problem somewhere else?

 

Any codes?

 

Just an p0175 for fuel trim. No supporting codes to give me a clue what's wrong

 

The maf reading engine off is concerning. I will check one of mine for MAF readings tomorrow and report back. My guess is you have a bad MAF. Why did you change it?

 

I swapped it because I'm to stupid to leave crap that isn't broken alone. I put the old maf back in got same reading of 5.5. Might just be a default value. This thing is clearly running very rich with no explanation. Cats appear to be toast but is that a cause or effect?

 

Confirmed this morning mine which is running perfect has basically the same readings - do you have video of the 02 voltages on a graph ie torque app? If they are cycling correctly it is not rich.

 

Very unlikely but could it be an injector stuck open?

 

Here are a couple screens of 02 graphs. I'm concerned the downstream are fluctuating so much but no code set.

 

OK, with those graphs it cannot be running rich. The 02's are cycling right at stoichometric, so it can't be rich. If it was rich they would be at 1 volt all the time. The downstream cats look like the upstreams are bad (not burning off the excess) and they are cycling in time with the ECU injector cycle.

 

I thought the cats looked suspect as well. At steady cruise they sit at .6 but any more than slight throttle they can't seem to keep up. One also seems to .1 for a second or two sitting at a light.