P0133 code (pending), but no CEL

[JC-RH]

All along I have been getting a CEL, but it was mostly for the downstream O2 sensor due to no cats (P2270).

I recently had a couple cats welded onto my x-pipe, and it resolved my gas smell coming from my exhaust. Other than JLT RAI, Mac longtubes, Mac Pro-chamber, and Borla Ataks, the car is stock (engine wise). It is on stock tune.

I’m still getting the occasional P2270 code, which I plan to put some de-foulers in to resolve. However, I’m now getting P0133, which is a “slow to respond” upstream O2 sensor.

In my research, it could be the actual sensor or it can be an exhaust leak. The car has 50k miles.

The scanner shows P0133 as a “pending” code, and the actual Check Engine Light has not been triggered by it. I’m getting about 10 MPG with pretty conservative city diving. What are your thoughts?

Thank you.

 

[JC-RH]

I also want to add that the car idles well right on 750 RPMs. I also have an AEM wideband that reads 14.5-14.7 at idle/cruising once it’s warmed up.

 

[01yellercobra]

The slow to respond code is because of the headers. A couple things need to be tweaked in the tune because the sensors are now further from the engine and take longer to warm up and react to changes in the A/F.

Are you the guy that was shifting under 2k around town?

 

[JC-RH]

LoL. I guess there aren’t too many of us. The car has not been tuned.

So if it’s just the positioning of the sensor and I don’t plan to do a tune, should I just live with it?

I have heard somewhere that a tune is recommended by just having headers. Would a tune give me more power and better MPG?

I live in Miami FL and I’m having trouble finding a shop nearby. How do those tunes that are emailed to you work, and would you recommend one?

 

[01yellercobra]

Did you start revving it out like I mentioned in the other thread? We have a relatively small engine. They don't like low RPM.

If you don't want to get it tuned you'll just have to live with it. It really shouldn't hurt the performance too much. The O2's are used at WOT anyway. I would recommend a tune just to get things to play nicely with each other. Plus a little extra power never hurt anymore.

Basically the tuner sends you a file of parameters they want you to log. You send them the log then they make adjustments based on that log. I would reach out to 04sleeper or MalcolmV8 on here.

 

[JC-RH]

When I first got the car, I was doing the occasional spirited drive. I was making frequent trips to the gas station though, so I decided to drive a bit more conservatively and log my MPGs. I just wasn’t expecting 10 MPGs while taking it easy around town. While I know you have to pay to play, it got me thinking that maybe something minor is not 100% and it’s leading to the low MPGs. Maybe a sensor or something along those lines. I figured the sooner I can addres it, the less money I would have to spend on gas.


Thank you for the suggestions. I’ll reach out to them.

 

[01yellercobra]

I doubt you have anything major going on. Shifting under 2k will hurt it the most. That's just lugging the engine.

 

[JC-RH]

I’ve been looking at the SCT X3 tuner. Would this work fine for my application? I’m still gathering information since this is my first time dealing with any type of tune.

Also, how much would a tune run for roughly?

 

[03' White Snake]

10 mpg sounds low. I get that with 800hp on E85.

Stock motor on 93, I was getting 20 mpg cruising on the highway. I don’t remember city driving. You are leaving a lot on the table with the car not tuned.

 

[01yellercobra]

I’ve been looking at the SCT X3 tuner. Would this work fine for my application? I’m still gathering information since this is my first time dealing with any type of tune.

Also, how much would a tune run for roughly?

It should. But best bet is to talk to a tuner first. I've heard of tunes ranging from $300 to $700. All depends on what's needed.