OMG massive performance increase....with a twist!

[soccerballtux]

OK well that definitely explains it

And thanks for answering the question in a non condescending manner. Some people are just assholes I swear D:

BTW, how often should you change your o2 sensors? Since they're relatively cheap, I won't wait until I get a engine code the next time.

best with every oil change. That's how often I do mine on my scion tC bro.

 

[Carfax83]

OK, then google O2 sensor extension and buy them on ebay for your post catalytic sensor(s). Put them between the bung and the sensor and you will not be getting P0420 or P0430 again. They cost $10 each shipped or you could make your own under $5.00 by putting two spark plug anti-fouler together but you have to drill one of them to pass through the sensor end. ebay is easier.

Yeah, I heard about those already. I'll definitely consider it, but honestly, having the code generate itself every 500/600 miles isn't that big of a deal to me. Only takes me 1 minute to delete it.

Which brand of O2 sensor costs so little? Most OEM NTK or Denso are in the $100 range.

Bosch. I assume that when you say $100, you're talking about a single O2 sensor and not a pair am I right?

If so, thats an outrageous price. Even the Densos cost $50 bucks at Autozone.

I've heard that Bosch makes the sensors for Denso as well, so they're the same product, just different name.

The butt dyno strikes again.

Seriously dude, the butt dyno can exaggerate at times, but I don't think it's exaggerating this time. And besides, while the butt dyno can be mistaken, the fuel gauge is much more accurate. I'll see at the end of the week how much it costs me to fill up.

On average, it usually costs me $50 for premium and I fill up when the gauge is at the 1/4 mark.

best with every oil change. That's how often I do mine on my scion tC bro.

How often do you change your oil?

 

[xapo99]

Well then after reading that line I just stopped.

Nothing can change RPM at speed unless you change tire diameters or gear ratios.

Or the gear you are in

 

[Elganja]

changing your o2 sensors so often is solving the problem in the wrong way.. the guy saying he changes his every oil change has to be trolling

your problem is your tune. it is running way to rich and destroying the o2 sensors OR there is another problem you need to diagnose

fyi, don't call the problem solved until you drive the car for a while... there is a good chance the code will come back. And when it does, it has the potential to put the car in a "limp" mode (usually pulling timing or something along those lines) to protect the engine.

go get your car tuned at a reputable place using your predator tuner (tbh, I'm not a diablo fan... I'm a SCT fanboy)

 

[Carfax83]

changing your o2 sensors so often is solving the problem in the wrong way.. the guy saying he changes his every oil change has to be trolling

I agree, I don't know if he was being serious or not. Some people change their oil every 15k, or even 20k though.

your problem is your tune. it is running way to rich and destroying the o2 sensors OR there is another problem you need to diagnose

The tune I'm using is the 93 CAI tune. I never had problems before with this tune, so I doubt thats what it is.

I honestly think the O2 sensor was just going bad. It happens sometimes, even in stock vehicles long before they're supposed to go bad..

Also, it's possible the mechanic may have inadvertently damaged it when he put in the high flows 3 months back. That could explain the significant loss in power I noted when I drove off.

fyi, don't call the problem solved until you drive the car for a while... there is a good chance the code will come back. And when it does, it has the potential to put the car in a "limp" mode (usually pulling timing or something along those lines) to protect the engine.

Believe me, I have my eyes peeled. I want my car to run the way it is running now for as long as possible. Right now, it's running awesome!

go get your car tuned at a reputable place using your predator tuner (tbh, I'm not a diablo fan... I'm a SCT fanboy)

Yeah, I'm going to do this as well. There's a tuning shop named ET Motorsports close to where I live, so I'm going to check them out eventually to get a custom tune.

I'm installing an Airaid CAI tomorrow (or Friday), which will have much greater air flow than my present set up (1100 CFM I believe).

Right now, I'm running an Afe Pro dry S filter, with a K&N air tube. The reason why I have this hybrid set up is because the Afe filter came with my ram air hood when I ordered it, a long with the air box. My K&N filter would not fit in the air box at all.

I'll take pics after I get it installed. :thumbsup:

 

[DominionSeraph]

Seriously dude, the butt dyno can exaggerate at times, but I don't think it's exaggerating this time. And besides, while the butt dyno can be mistaken, the fuel gauge is much more accurate. I'll see at the end of the week how much it costs me to fill up.

On average, it usually costs me $50 for premium and I fill up when the gauge is at the 1/4 mark.

...

 

[SparkyJJO]

/facepalm

An O2 sensor can cause lousy performance, yes, but it won't affect the RPM of the engine at highway speed when the transmission is in lockup (as any automatic transmission in the last 15 years does, at least), and it won't make your gas tank smaller so when you fill up at 1/4 tank it'll still take the same amount to fill it as before.

 

[Carfax83]

/facepalm

An O2 sensor can cause lousy performance, yes, but it won't affect the RPM of the engine at highway speed when the transmission is in lockup (as any automatic transmission in the last 15 years does, at least), and it won't make your gas tank smaller so when you fill up at 1/4 tank it'll still take the same amount to fill it as before.

/double facepalm

What on earth are you guys talking about? Do you honestly believe I think that I'm going to pay less money if I fill my gas tank up at quarter tank?

How ridiculous is that? What I meant was, that I fill my gas tank up after a week's worth of driving, of which I usually have 1/4 tank left.

Since I'm getting better gas mileage though, at the end of the week I should have more than a quarter tank, hence less money spent at the fuel pump.

 

[Carfax83]

OK, got the Airaid CAI installed today. Took me about an hour to do, as the instructions were very clear, with only one exception.

Had to remove the air box that came with my ram air hood though, as the filter was too big to fit in it. Not a big deal though, as the Airaid heat shield is awesome.

The Airaid filter is freaking massive, but thats to be expected as according to an Airaid rep I spoke to, it's one of the highest flowing filters they have.

Just to give you an idea of the size of it, here's a picture of it next to the Afe Pro S dry that I had on before:

And here's a pic of the air tube next to the K&N that I had:

As you can see, the Airaid is noticeably wider..

A pic of the final install:

After driving off for the first time, I noticed that the car felt a little less powerful than before. It was to be expected though, as it takes time for the PCM to adjust to the greater air flow from my previous set up so I was definitely running a little lean.

Reinstalling the Diablosport 93 CAI tune removed the performance loss completely (new baseline parameters), and the car now feels noticeably more powerful than it did before. Throttle is also more responsive, and the engine is revving higher....sounds better too

It will take a few days for the PCM to fully adjust and calibrate for the greater air flow though, so I expect the performance to keep increasing until it reaches the optimal level.. :thumbsup:

 

[LTC8K6]

Is the throttle body bigger?

 

[Carfax83]

Is the throttle body bigger?

Yeah, I have a 85mm BBK throttle body. The stock OEM size is 80mm, but the boring is slightly narrower. With the BBK, it's 85mm all the way through..

Thats probably why the coupling was so hard to put on. That alone took me about 15 minutes. D:

Anyway, I'm very pleased with the Airaid CAI. I drove to Wingstop this evening, and I can definitely feel the increased power. Hopefully, it will improve even more within the next few days as the PCM adjusts for the increased air flow.

 

[Carfax83]

OK guys, I need some help again. The damn P0133 code came back.....again!

Same code as before, but how the hell has it gone bad already? It hasn't even been a month since I had the new O2 installed!

Also, my car is still running great, unlike before when it had very bad fuel economy and performance, which are symptoms of a bad O2 sensor.

 

[FuzzyDunlop]

FROM THE OP:

I read the code with my diablosport predator tuner, looked it up online and found that it's likely caused by a malfunctioning upstream o2 sensor on the driver's side....or a leak in the exhaust.

How do you KNOW that you done have a leak?


OH, and also with the aftermarket cones
http://forums.nicoclub.com/debunking-the-k-n-myth-why-oem-is-better-t180100.html

and
http://forums.anandtech.com/showthread.php?t=2040364

 

[Carfax83]

FROM THE OP:


How do you KNOW that you done have a leak?

I never said I knew for sure... I just doubted it.

But now I'm doubting that doubt, because apparently, my bank 2 sensor is throwing the same kind of code (P0153).

So both my O2 sensors are messed up now

But wouldn't there be a smell if there was a leak, or some other indication? Thats what gets me more than anything. When I first started this thread, I had all the major symptoms associated with an O2 sensor failure, ie poor gas mileage, loss of power, sluggish acceleration etc....

But now I have none of those. My gas mileage, power etc is better than it's ever been.

So now I'm going to take my car to the mechanic that installed my headers and have him check the torque on the bolts..

OH, and also with the aftermarket cones
http://forums.nicoclub.com/debunking-the-k-n-myth-why-oem-is-better-t180100.html

and
http://forums.anandtech.com/showthread.php?t=2040364

I'm not getting suckered into that discussion.... BTW, I'm also using Airaid, not K&N...

 

[FuzzyDunlop]

I'm not getting suckered into that discussion.... BTW, I'm also using Airaid, not K&N...

nah, you just got suckered into buying one :awe:

 

[FuzzyDunlop]

Hey, but so did I LOL.

 

[Harrod]

I was kindof hoping the K&N rep would jump into this thread.

 

[Carfax83]

nah, you just got suckered into buying one :awe:

CAIs can make a very noticeable difference in performance, especially on modified cars. Lots of dyno tests and personal testimonials from car enthusiasts to prove it..

That said, I do think K&N is vastly overrated. There are much better CAI manufacturers out there; Airaid and AFE in particular..

At any rate, I found out the problem with my O2 sensors. The problem was, that they were cheap pieces of crap that have a tendency to give out very quickly! D:

Seriously, I researched the Bosch aftermarket O2 sensors on the net, and I found all sorts of accounts of them giving out after only a few months of use.. I only paid 23 bucks a piece for them, so I guess I got what I paid for..

The NTK and Denso O2 sensors are rated much more highly than the Bosch ones, and in fact, I think NTK is the company that makes the OEM MOPAR sensors..

So I bought 2x NTK O2 sensors from Advanced Auto Parts yesterday and installed them, and the CEL went off as soon as I started the vehicle.

The Bosch O2 sensors were still under warranty, but I could only get a replacement for them, and not a refund....

A guy I spoke to at Autozone also told me that using fuel additives can also shorten the life of the O2 sensors. Is there any truth to this?

I use Chevron with Techron concentrate every 3000 miles or so, plus I also use premium gas, which is known to have greater quantities of fuel additives.