P0171 and P0420

[aeroblu22]

looked em up online on alldata during class today

P0171-Fuel Trim System Lean

P0420-Catalyst System Low Efficiency

i'm pretty sure i know why the cat one's showing. just wondering about the system lean code. me and another ran through the whole checklist off of Alldata with the OBDII scantool, and all the readings on the scanner were within norms. some of the other students tried to convince me that the lean code was being thrown because my larger exhaust didn't have enough backpressure for the o2 sensors to work [img]{SMILIES_PATH}/rolleyes.gif[/img]

so since all the sensors are showing normal readings, wtf could it be?

[slowion2]

lean code may be from from the MAF being dirty, clean it off with some brake cleaner and then try it off with a CLEAN towel

other code might be a bad cat, hard to say.

[Rear-Vue]

ahh finally someone with my asshole codes..

there is the obviously vaccum leek to check for as well as the maf sensor little thing getting dirty apparently they are very anal those things..

cheap stuff first clean it with trottle body cleaner thats wha ti would do.

could use a vaccum line or a asiliscrope (sp>?) to lisen for any hissing around the intake , tb or any vaccum lines.

[heavyfootedion]

careful using brake clean, ive seen some maf getting messed up if you use to much of it!

[slowion2]

ahh finally someone with my asshole codes..

there is the obviously vaccum leek to check for as well as the maf sensor little thing getting dirty apparently they are very anal those things..

cheap stuff first clean it with trottle body cleaner thats wha ti would do.

could use a vaccum line or a asiliscrope (sp>?) to lisen for any hissing around the intake , tb or any vaccum lines.

it's on an ion, it's a little different to clear up because there's less areas for a potential vaccuum leak.

careful using brake clean, ive seen some maf getting messed up if you use to much of it!

that's why you don't drown the fucker in it, just clean it off...

[aeroblu22]

note to self..."do not drown the fucker" [img]{SMILIES_PATH}/lol.gif[/img]

actually, that's a pretty good point to make, thanks.

[S.Bretz]

The system needs to toggle slightly rich to slightly lean in order for the cat to really function properly. If its just lean, then the catalized gases will be out of wack a little...Its like trying to make pizza with only crust and sauce, but no cheese and toppings...you need it all there to be right.

[slowion2]

^^^great explanation right there

[MGM1979]

So, he's got a plain cheese pizza stock in his Cat? :roll:

[aeroblu22]

i'll check the combustibles storage closet at school monday for brake cleaner or MAF cleaner. (that famous saturn cheapness

[DTDSasquatch]

A long time ago, there was a thread on SaturnFans...

(ok, are you done laughing?)

... in which this (or something similar... I think there was smog testing involved) turned out to be the front O2 sensor. That was on an S-series, not an Ion, but it's probably worth considering if the MAF turns out to be okay.

[S.Bretz]

Do you have an air filter that requires oil...like a K&N? If so, that oil will fuck up a MAF filament wire.

[therealm0rh0us]

a bad o2 will set a lean code sometimes and if it aint workin right itll cause an efficiency code
and mass air systems suck
oil + mass air ftl

[aeroblu22]

yes, sam, i have a CAI, so it is oiled. however after i got the new version of the fujita, it stopped throwing codes. [img]{SMILIES_PATH}/confused.gif[/img] only started the codes again after i had my ignition module replaced when i blew out the original.

gonna pick up a new cat this week anyways for me to hollow out and weld on at school in january, so probably a moot point to check what's causing the cat efficiency code.

thanks for all the help, i'll start checkin stuff tomorrow.