ARH Long Tubes, Stock Air Intake. Weird Throttle response, Help!

[MartyZ]

Hey everyone, I did some searching and haven't come up with a good answer other than to contact @Wild one or Moe's for information.

Maybe someone here knows:
5.7l 4x4
My exhaust system is ARH long tubes with High Flow CAT's into 3" In/Out Borla Pro XS, into stock tail pipe and resonator (basically just the bend over the rear axle to the tip is stock)

I have ARH headers installed with the Stock Air box.
Idle is great, accelerating is weird now. My RPM's will fluctuate 100 or so during throttle, enough to hear the motor going up and down in RPMs while accelerating. I'm assuming that I'm starving the motor of air with the stock setup.
Either that or my back pressure is off with the 3" Borla? ( I know, I'm a firm believer of backpressure being a myth but I'm now questioning everything again.)
Can anyone confirm this?

If an air intake upgrade is required, what are the benefits of doing CAI vs Veraram?
Is a tune required to alleviate this issue?
and last question, will I need an upgraded throttle body or injectors if I do this?

 

[Fast69Mopar]

Hey everyone, I did some searching and haven't come up with a good answer other than to contact @Wild one or Moe's for information.

Maybe someone here knows:
5.7l 4x4
My exhaust system is ARH long tubes with High Flow CAT's into 3" In/Out Borla Pro XS, into stock tail pipe and resonator (basically just the bend over the rear axle to the tip is stock)

I have ARH headers installed with the Stock Air box.
Idle is great, accelerating is weird now. My RPM's will fluctuate 100 or so during throttle, enough to hear the motor going up and down in RPMs while accelerating. I'm assuming that I'm starving the motor of air with the stock setup.
Either that or my back pressure is off with the 3" Borla? ( I know, I'm a firm believer of backpressure being a myth but I'm now questioning everything again.)
Can anyone confirm this?

If an air intake upgrade is required, what are the benefits of doing CAI vs Veraram?
Is a tune required to alleviate this issue?
and last question, will I need an upgraded throttle body or injectors if I do this?

Okay. Let's start from the beginning. How long have the headers installed?

When did you first notice the engine RPM surging?

Is the RPM surge occuring during part throttle/normal acceleration or during WOT pulls?

Does the engine RPM surge occur in every gear? Have you tried to duplicate the issue in each gear while accelerating?

Don't question yourself about the
back- pressure. It is irrelevant.

If this issue started after the header install the first thing I would inspect is the oxygen sensors. Are they all plugged in? Seated properly?

Next, take a look at the knock sensors on each side of the block. There have been instances where the knock sensors detecting false knock from the exhaust tone running through the header tubes. If the knock sensors are detecting false knock it can be enough for the PCM to pull timing and you will feel the engine surge.

A tune is not necessary to run long tube headers. Will it make more power with a tune and the headers? Yes, it will. The stock airbox in not a problem and adding a larger throttle body will not alleviate your issue.

A good scan tool is required. We need to see what the engine is doing. What do the fuel trims look like?

 

[MartyZ]

@Fast69Mopar
Headers have been on for about a week now. Issue started a few days after the installing was complete.

Normal Throttle:
2nd - 5th Gear: It does surge a little at normal throttle, almost unnoticeable.

Wide Open:
1st - 3rd Gear: Wide open throttle I can feel and see surging on the RPM Gauge.
4th - 5th Gear: I have noticed my RPMs run much higher before a gear change at full throttle, I have not noticed a surge getting there though.

All Sensors are plugged in, I had to use 2 Extension Cables for the Drivers Side Connections.
I am very sure I plugged them in right (white vs black) but as for which bank is plugged into which sensor, I'm starting to think I could have flipped those.


I did throw 2 codes, I ordered 2 more O2 sensor extensions assuming I was fouling the sensors before I read the codes.

The code Read "O2 Sensor 1/1 Slow Response" & "O2 Sensor 2/1 Slow Response"
I cleared the codes but still have the surge.

I currently have an Alpha OBD, is this advanced enough to read fuel trims?
As for the knock sensors, What's the best way to know if its picking up the new headers noise?

 

[Fast69Mopar]

@Fast69Mopar
Headers have been on for about a week now. Issue started a few days after the installing was complete.

Normal Throttle:
2nd - 5th Gear: It does surge a little at normal throttle, almost unnoticeable.

Wide Open:
1st - 3rd Gear: Wide open throttle I can feel and see surging on the RPM Gauge.
4th - 5th Gear: I have noticed my RPMs run much higher before a gear change at full throttle, I have not noticed a surge getting there though.

All Sensors are plugged in, I had to use 2 Extension Cables for the Drivers Side Connections.
I am very sure I plugged them in right (white vs black) but as for which bank is plugged into which sensor, I'm starting to think I could have flipped those.


I did throw 2 codes, I ordered 2 more O2 sensor extensions assuming I was fouling the sensors before I read the codes.

The code Read "O2 Sensor 1/1 Slow Response" & "O2 Sensor 2/1 Slow Response"
I cleared the codes but still have the surge.

I currently have an Alpha OBD, is this advanced enough to read fuel trims?
As for the knock sensors, What's the best way to know if its picking up the new headers noise?

View attachment 467229

1/1 and 2/1 O2 slow response means the oxygen sensors are not switching like they are supposed to. When the sensor gets like this the commanded AFR can't be reached in a timely manner and the engine can run bad.

Also, why did you have to use 2 x extensions on the left/driver side?

Did you have to use an extension anywhere else?

Are you sure you don't have the upstream and downstream oxygen sensors swapped?
Just make sure.

With the slow response DTC's I would replace the upstream oxygen sensors with Mopar units.

I don't use AlfaOBD so I'm not sure if you can see live data or the adaptive memory and fuel trims.

 

[Wild one]

Hey everyone, I did some searching and haven't come up with a good answer other than to contact @Wild one or Moe's for information.

Maybe someone here knows:
5.7l 4x4
My exhaust system is ARH long tubes with High Flow CAT's into 3" In/Out Borla Pro XS, into stock tail pipe and resonator (basically just the bend over the rear axle to the tip is stock)

I have ARH headers installed with the Stock Air box.
Idle is great, accelerating is weird now. My RPM's will fluctuate 100 or so during throttle, enough to hear the motor going up and down in RPMs while accelerating. I'm assuming that I'm starving the motor of air with the stock setup.
Either that or my back pressure is off with the 3" Borla? ( I know, I'm a firm believer of backpressure being a myth but I'm now questioning everything again.)
Can anyone confirm this?

If an air intake upgrade is required, what are the benefits of doing CAI vs Veraram?
Is a tune required to alleviate this issue?
and last question, will I need an upgraded throttle body or injectors if I do this?

The hi-flow cats and no tune might be your issue. Try what Fast is saying,and another old school trick that might help ,is to run anti-foulers . I like the stacked version of them,with the bottom anti-fouler stuffed with steel wool.You have to drill out the top anti-fouler,so the 02 sensors will fit through them,then stuff the bottom one full of steel wool. My wifes last 2 Challengers have been untuned and catless,and the anti-fouler trick has kept the computor happy on both cars.

 

[MartyZ]

Also, why did you have to use 2 x extensions on the left/driver side?

Did you have to use an extension anywhere else?

The ARH Headers put the O2 Sensors in a new location vs the OEM setup. My OEM sensor cables were not long enough to reach the harness.

The hi-flow cats and no tune might be your issue. Try what Fast is saying,and another old school trick that might help ,is to run anti-foulers . I like the stacked version of them,with the bottom anti-fouler stuffed with steel wool.You have to drill out the top anti-fouler,so the 02 sensors will fit through them,then stuff the bottom one full of steel wool. My wifes last 2 Challengers have been untuned and catless,and the anti-fouler trick has kept the computor happy on both cars.

I ordered a second set of anti-foulers to attempt this. When they get delivered I'm going to do this trick and verify my wiring.

 

[Fast69Mopar]

The ARH Headers put the O2 Sensors in a new location vs the OEM setup. My OEM sensor cables were not long enough to reach the harness.


I ordered a second set of anti-foulers to attempt this. When they get delivered I'm going to do this trick and verify my wiring.

Make sure you put the non-foulers on the downstream sensors.

 

[MartyZ]

Make sure you put the non-foulers on the downstream sensors.

I ordered 4 originally. I have the non-Foulers on upstream and downstream. I ordered 2 more to add a second set to the upstream. Is this correct?
Should i not run the de-foulers on the downstream?

 

[Fast69Mopar]

I ordered 4 originally. I have the non-Foulers on upstream and downstream. I ordered 2 more to add a second set to the upstream. Is this correct?
Should i not run the de-foulers on the downstream?

Do not run the non-foulers on the upstream. Doing so will cause the engine to surge and run poorly.

You need the non-foulers on the downstream oxygen sensors only.

You need the upstream oxygen sensors in direct contact with the exhaust flow for proper fuel control.

 

[MartyZ]

@Fast69Mopar Wow, You may have just solved my problem. I put the non-foulers on all of them.

So I should do a double set on the downstream and use steel wool?

 

[Fast69Mopar]

@Fast69Mopar Wow, You may have just solved my problem. I put the non-foulers on all of them.

So I should do a double set on the downstream and use steel wool?

Yes. Double stacked non-foulers on the downstream oxygen sensors only and packed with steel wool.
I can guarantee with near 100% certainty that having the non-foulers installed on the upstream oxygen sensors is causing your issue.

On a cold start the sensors do not do anything until they reach a predetermined temperature hence why they have heaters built in. During warm-up the PCM is in open loop and ignores the oxygen sensors until a certain temp is reached. Then, the sensors warm up and begin to provide a voltage to the PCM. The only way the upstream oxygen sensors can provide the proper voltages that the PCM is looking for is if the sensors have exhaust flowing through the tip of the sensor. When you add a non-fouler to the sensor you are moving the sensor further away from the exhaust flow and this causes the sensor to produce a lower voltage to send to the PCM. Lower voltage means lean. Moving the upstream oxygen sensors further away from the exhaust flow will also cause the 1/1 and 2/1 slow response DTC's because the oxygen sensors don't have enough exhaust flowing through them to produce the voltage so the sensors slow down hence the DTC's.

 

[Wild one]

@Fast69Mopar Wow, You may have just solved my problem. I put the non-foulers on all of them.

So I should do a double set on the downstream and use steel wool?

Yup and take the anti-foulers out on the front 02's like Fast said. Having the front 02's on anti-foulers might be your issue.

 

[DILLIGAF]

You need a custom tune dude no other way around it.

 

[MartyZ]

Thank you all for the fast responses. I took the spacers off the upstream sensors and added them to the downstream. Packed steel wool between the adapters and reset the codes. My drive to work in the morning will prove some issues out. I will report any changes. You guys rock!

 

[Fast69Mopar]

Thank you all for the fast responses. I took the spacers off the upstream sensors and added them to the downstream. Packed steel wool between the adapters and reset the codes. My drive to work in the morning will prove some issues out. I will report any changes. You guys rock!

Yeah man. Let us know how it runs. I'm betting it's back to the new normal with the non-foulers removed from the upstream oxygen sensors.

 

[MartyZ]

Update: This solution corrected the surging issue, She is running great. Lots of power, no surging RPMs. Thanks again for all the help everyone.

 

[Fast69Mopar]

Update: This solution corrected the surging issue, She is running great. Lots of power, no surging RPMs. Thanks again for all the help everyone.

Yeah man. Oxygen sensors can cause all sorts of problems. When we overlook things is when they can drive us crazy.

 

[MartyZ]

Ok, I spoke too soon. It threw Running Rich codes on the way home. I'm gonna stuff more steel wool into the downstream sensor adapters. But no Surging RPMs still. I'm gonna let it cool off and attack it tonight if it doesn't rain.

 

[DILLIGAF]

I ran into this issue 7 years ago when I installed LT headers. The CELs will keep coming back unless you do it the right way.

 

[Nick@GotExhaust]

Ok, I spoke too soon. It threw Running Rich codes on the way home. I'm gonna stuff more steel wool into the downstream sensor adapters. But no Surging RPMs still. I'm gonna let it cool off and attack it tonight if it doesn't rain.

I am going to PM you an option