EVAP issues

[lukecibilich]

had the SES light come on last week, scanned it, got some codes

-EVAP MALFUNCTION. and -LARGE LEAK, LOW SYSTEM VACUUM.
possible causes?: (gas door open, unplugged charcoal canister, broken purge solenoid)

-P0420:Catalyst Efficiency Below Threshold. or -P0431:Warm Up Catalyst Below Threshold. it's either one i forgot which hha
possible causes: (bad o2's or cats) ihad a "running rich" code for months untill i got a re-tune, so maybe I slightly messed-up/melted the cats.. idk how possible that is, maybe it needs to be lean not rich to do that

-RANDOM/MULTIPLE CYLINDER MISFIRE
causes?:(i would say the likely cause is from the problem with the cats or o2's or maybe a header leak) I don't think it's a plug or a wire b/c it's random/multiple cylinders not the same one over and over) the misfire must be slight b/c i don't think it drives different or hesitates


When i got the light it said "tighten gas cap", the cap was tight so idon't think it's the problem. Im guessing it's a loose hose. soo.. MY QUESTION IS SHOULD I JUST DITCH ALL THAT EVAP STUFF?



& my rear O2's are off and have been off
also i think it was the STFT's, but lowest it was reading was (5% - 7%) at idle completely warmed up after sitting for a while ...if somebody knows somthin bout that tell me.

[lukecibilich]

thanks for all the opinions and info guys! lol

decided to just turn all the codes off in the tune and remove it

[txarkitekt]

had the SES light come on last week, scanned it, got some codes

-EVAP MALFUNCTION. and -LARGE LEAK, LOW SYSTEM VACUUM.
possible causes?: (gas door open, unplugged charcoal canister, broken purge solenoid)

-P0420:Catalyst Efficiency Below Threshold. or -P0431:Warm Up Catalyst Below Threshold. it's either one i forgot which hha
possible causes: (bad o2's or cats) ihad a "running rich" code for months untill i got a re-tune, so maybe I slightly messed-up/melted the cats.. idk how possible that is, maybe it needs to be lean not rich to do that

-RANDOM/MULTIPLE CYLINDER MISFIRE
causes?i would say the likely cause is from the problem with the cats or o2's or maybe a header leak) I don't think it's a plug or a wire b/c it's random/multiple cylinders not the same one over and over) the misfire must be slight b/c i don't think it drives different or hesitates


When i got the light it said "tighten gas cap", the cap was tight so idon't think it's the problem. Im guessing it's a loose hose. soo.. MY QUESTION IS SHOULD I JUST DITCH ALL THAT EVAP STUFF?



& my rear O2's are off and have been off
also i think it was the STFT's, but lowest it was reading was (5% - 7%) at idle completely warmed up after sitting for a while ...if somebody knows somthin bout that tell me.

Well, as far as the EVAP stuff, I would just disable or turn the EVAP stuff off in the tune. I really don't think there is a need to try and screw with it.

For the P0420 code, if you still have cats--they are bad by now, so I would just have them removed. I would just go ahead and throw some LTs and an ORY in there. I would also get some new O2 sensors just for good measure.

The Random Misfire could be a bunch of things. I would start with replacing the plugs with NGK replacements. Nothing fancy, but I recommend NGK TR-6 plugs from O'Reillys. Make sure to set the gaps properly. Then if the code still exists, look at the fuel system...FPR, fuel filter, overall fuel pressure, etc. Dealing with a Random Misfire code is so general that I could type for hours about the things you could do to correct it...

[lukecibilich]

thanks, im goin to my tuner this weekend and getting that taken care of ,should i physically remove everything or leave it on

i put the tr-6's on there about 6 months but wasn't able to gap them

....lt's are on the list