Bosch 02 sensor??

[s13 Jrock]

so while i was sitting here tryna figure why my car doesn't wan to idle or run right, and looking at AFR gauges, i started to think as to what I've changed between now and the last time to the motor was running that may be causing it to run poorly. and it came down to the turbo (stoke ca > s15 bb) and the o2 Sensors (stock ca > bosch 13276) i noticed that the wires on the bosch are different than colors than the OEM ca ones. and when i turn on the motor, i noticed if i cup the end of the MAF about half way with my hand, the motor will idle and rev pretty much perfect, so with all that being said.. is the bosch supposed to be a direct drop in or do some wires need to be switched around? i only replaced it because i switched turbo elbows and couldn't get the old CA 02 out. I'm hoping that this is my issue.

Bosch wires = White/Black/white

OE Ca 02 = Red/White/black.

[float_6969]

That's not your issue. Those wires are all correct, even if the colors aren't the same. On the stock O2 sensor, the Red and Black wires are for the heater circuit and the white wire is for the signal. On the Bosch sensor, the white and white wires are for the heater circuit and the black wire is the signal.

Cupping the MAFS to make it work almost always indicates a turbulence issue. You didn't happen to install the MAFS the wrong direction, did you?

[s13 Jrock]

aww man. was hoping that was gunna be it. but from what i know the MAF is on properly. the side with the 4 holes that bolted to the oem air box are on the outside (receiving end) while the other edge sits into the oem suction pipe.

[float_6969]

no codes?

[s13 Jrock]

Nope. 55 all good. It's so confustrating. I guess I was thinking it could be the 02 because the clip on the oem CA the black wires on the Far right I believe and the bosch is not. And I assumed it would be a ground since it was black. But this sucks I'm running out of Ideas. Last thing we were thinkinking of trying is running my Z32 maf and hooking up my safc to adjust just that.

[float_6969]

Have you tried swapping the MAFS? Have you checked the voltage at idle coming from the MAFS? Voltage when you cover it with your hand and it runs OK?

[s13 Jrock]

don't have another ca maf to try out, just the z32. we checked voltage with the ignition on and it was i believe around 11 - 13 volts. but with the car running and it trying to die and idle, it was around 1 to 2v which, according to the fsm is the correct voltage, but that seems to low right? kinda confused

[s13 Jrock]

Have you tried swapping the MAFS? Have you checked the voltage at idle coming from the MAFS? Voltage when you cover it with your hand and it runs OK?

just got done retesting the voltage. with hand over maf, was getting 1.6-1.7v. with out hand and stumbling dropped to about 1.3-1.5v

[float_6969]

EF&EC-85, says voltage from ECU pin 27 (the green w/a black stripe wire if you're checking at the MAFS) to ground at idle should be 1.5v. The 1.3-1.5v is the proper voltage at idle.You covering the MAFS is raising the voltage, which would inject more fuel for the same amount of air flow. You have a vacuum leak somewhere, or the fuel pressure is low.

[s13 Jrock]

EF&EC-85, says voltage from ECU pin 27 (the green w/a black stripe wire if you're checking at the MAFS) to ground at idle should be 1.5v. The 1.3-1.5v is the proper voltage at idle.You covering the MAFS is raising the voltage, which would inject more fuel for the same amount of air flow. You have a vacuum leak somewhere, or the fuel pressure is low.

well i set the fuel pressure according to the sticky, and it seems to be in the ball park at proper idle, so i think thats okay. i kinda feel like its a vac leak also because when i do putt it around my neighborhood, when i clutch in to shift the revs kind of linger where ever i clutch in at and drop back down pretty slowly. but the thing is i can't find it. I've tried the propane method, carb cleaner way, sprayed foamy water on couplers and for the most part everything seems fine. i think i may have noticed that with the idle screw, the more i let it out, i hear a type of vac leak, but thats because I'm unscrewing it out right? i did also change out the 2 Main intake manifold gaskets with auto zone ones because both oem ones got damaged when taking apart the intake mani, but don't think that would matter would it? are there any vac leaks areas that CAs are known for that I'm missing, i mean there aren't to many hoses to get a leak from. or are there..?

[float_6969]

[youtube]http://www.youtube.com/watch?v=AL3jbcrq ... e=youtu.be[/youtube]
http://www.frozenboost.com/intake-leak- ... e98bad169b

[float_6969]

And ignore the bit about the PCV valve. Our valves are different and should NOT leak when under pressure. That being said, even if it does leak, all it will do is pressurize the crankcase, which shouldn't leak anyway. It's also really important not to use a lot of pressure. 10-15psi is plenty to find any leaks you may have.

[s13 Jrock]

And ignore the bit about the PCV valve. Our valves are different and should NOT leak when under pressure. That being said, even if it does leak, all it will do is pressurize the crankcase, which shouldn't leak anyway. It's also really important not to use a lot of pressure. 10-15psi is plenty to find any leaks you may have.

will definitely be giving this a try. quick question though, without the maf plugged in, would the possible vac leak have the same affects? because with no maf plugged in, it idles steady at about 900-1k. didnt really look at the revs. but it sounded perfect

[float_6969]

Without the MAFS, the effects of the leak go away and the car will often run better.

[s13 Jrock]

Without the MAFS, the effects of the leak go away and the car will often run better.

Okay. Just making sure. Gotta try and get to or buying and air comp next. So it may be a while before I get to actually try this out :/

[s13 Jrock]

so, i made the cap to test for leaks. main issue what the fat hose that came off the oil filter area for crank cad ventilation. it idles better, drivable for the most part, but still holds the revs a little when i go to shift, and slight hesitations here and there. any other ideas?

[float_6969]

Holding revs is a leak in the intake manifold somewhere. If you did a pressure test and it came out OK, then one of the idle control valves is sticking open. Try taking the IAA off and cleaning it out as well as cleaning the FICD and the AAC. What rpm does it idle at? The Air Regulator is notorious for getting stuck open and not letting the car idle down like it should.

[s13 Jrock]

It will idle between 850 - 1100. More on the 1100 side. I can't seem to find anywhere to buy those gaskets for the idle control stuff, only in the gasket kit. That's why I haven't taken it apart yet. Is there a way to just get those by them selves

[float_6969]

Idle should be 850 +/-50 rpm. 1100 is way too high. The next time it idles that high, try plugging the line for the air regulator (the valve under the throttle body) and see if the idle goes down. If it does, the air regulator is sticking open (they do that A LOT) and it needs replaced. Don't bother trying to clean it. I've NEVER had that work long term.