CEL still on???

[Super Cubano]

I would definitely NOT replace an o2 for a lean code. youre setting yourself up for disappointment with that incorrect diagnosis

X2 If you had O2 issues you would likely have O2 codes. Lean codes on both banks typically indicate a vacuum leak, low fuel pressure, or dirty mass air flow sensor. I would suggest taking it to a GOOD shop for proper diagnosis instead of dumping a bunch of money on guessing. If you need a good shop in Arlington pm me.

[TENGRAM]

ugh. OBDII, huh?

I didn't realize that OBDII had separate codes to differentiate faults with the o2 sensors from actual lean conditions. Disregard my previous advice about replacing the o2 sensors.

<< wandering back to his narrow realm of expertise.

[91CoupeMike]

Since the back two are good, in theory if I were to swap the back 02's ( that I know work) to the front, the lean code would clear and the code for failed cats would appear??

No.

The front measure air/fuel ratio

The rear measure catalytic effieciancy.

[FoxBodyNick]

X2 If you had O2 issues you would likely have O2 codes. Lean codes on both banks typically indicate a vacuum leak, low fuel pressure, or dirty mass air flow sensor.

This.

[LS1Goat]

1. An educated guess is not a diagnosis.
2. In my experience when o2 sensors go south they most often return a lean/not switching signal. With only 125k miles and hardly any modifications I don't think my assumption regarding the wiring and injectors is extraordinary; then, if there are no exhaust or vacuum leaks, and no other codes, what else could be the cause?

Sure, he could go in and do a few continuity/voltage tests on the o2s, check fuel pressure, and check for injector operation, but with unknown mileage on those o2 sensors it'd be easiest to replace them, especially since they are a maintenance item.

Whatever. I'm just putting in my 2 cents.

good advice.

[Cobraman]

So evidently, my CAI is pulling in more air than the computer can handle. What do I do from here? Buy a tuner? This has really become a nightmare.

[jdgregory84]

Your cold air is pulling in more than the computer can handle? Where did you come up with that? The only air going through there is gonna be the air that's sucked in when the throttle body opens. The mass air meter itself might be fucked up from the oil on the air filter, or just dirty. Also, did you not have MIL eliminators in place of the o2 sensors when you had the o/r pipe on?

If you don't hear any exhaust leaks (they're easy to hear, it'll sound like a tick) you've probably got a bad or dirty MAF meter. A bad meter can cause it to run lean, because it can't probably read the air being sucked into the engine. Find a stock MAF and drive it.

[TENGRAM]

So evidently, my CAI is pulling in more air than the computer can handle. What do I do from here? Buy a tuner? This has really become a nightmare.

That seems highly unlikely. It's possible, though, that the filter of your CAI is way too close to the MAF and the turbulence across the sensor is causing the issue. Have you tested it with the stock inlet?

[Cobraman]

Your cold air is pulling in more than the computer can handle? Where did you come up with that? The only air going through there is gonna be the air that's sucked in when the throttle body opens. The mass air meter itself might be fucked up from the oil on the air filter, or just dirty. Also, did you not have MIL eliminators in place of the o2 sensors when you had the o/r pipe on?

If you don't hear any exhaust leaks (they're easy to hear, it'll sound like a tick) you've probably got a bad or dirty MAF meter. A bad meter can cause it to run lean, because it can't probably read the air being sucked into the engine. Find a stock MAF and drive it.

took it to a shop. they said the computer thinks its pulling more air than it should.

[TENGRAM]

took it to a shop. they said the computer thinks its pulling more air than it should.

Name of shop?

[jdgregory84]

took it to a shop. they said the computer thinks its pulling more air than it should.

...and what reads how much air is being sucked into the engine? The MAF. Like I said, it's either faulty or dirty and can't read properly. Is the CAI your problem? Yes, and no. It's not your direct problem, but it is what's probably causing it. Small dirt particles can get through those high flow filters, or if the oil wasn't completely dry last time you cleaned it, it can suck that oil in and if it hits the wire on the MAF, it can short it out. Try cleaning it first. I think some chick actually posted a video of how she did hers not too long ago. If that doesn't work, you might try and find somebody with a factory one that they know works.

[Cobraman]

he said I needed to get the computer reprogrammed. is that bs?

[jdgregory84]

he said I needed to get the computer reprogrammed. is that bs?

In all honesty, it sounds like B.S. to me. I'm a big fan of trying the cheap shit first before going and spending $100 to have your PCM reflashed. Go to vatozone or o-reilys and pick up some mass air meter cleaner, spray the sensor off and make sure there's no more dirt inside the meter. Reset the computer by unhooking the battery, if that doesn't work, you can probably find a stock meter for $20<.

[lowthreeohz]

I've got a can of the crc electrical cleaner and the tx bit to clean your maf if you're near NRH/Hurst.

[shumpertdavid]

Like stated above, clean the maf, the 2 little "diode" looking things generate heat when powered up, the air coming across the "diode" removes heat. The computer uses the temperature drop to calculate the income air. If it gets a build up on the sensor (dirt, filter oil, etc) it acts like an insulator. Much like you wearing a coat when it's cold outside. A dirty maf will take away fuel at idle (makes for a lean condition), and add fuel driving (makes for rich condition). I've repaired several customer cars by servicing the maf and saved them hundreds of dollars in guesstimate repairs.