• Mustang Forums
  • 1979 - 1995 (Fox, SN95.0, & 2.3L) -General/Talk-

code 22 BAP vacuum line?

  • Thread starter Thread starter t1_5.0
  • Start date Start date Jun 28, 2024
T

t1_5.0

Member
May 6, 2024
18
2
13
California
Jun 28, 2024
#1
  • Jun 28, 2024
  • #1
What’s up everyone!

My 93 GT is currently getting codes 22 and 54. Being in CA won’t pass smog with a CEL so I’m trying to get these fixed asap.
I ordered and ACT and a BAP in hopes that it’s as easy as old sensors gone bad. My question is my BAP has a vacuum line attached to it as far as I know it shouldn’t. It should be open to atmosphere and plugged at the vacuum manifold correct? Could this possibly be a cause? Also the car does have an erratic idle until it stalls out especially before it warms up. I’ve read that a bad reading from BAP could cause those symptoms.

Again it’s a 93 GT with a C3W. I’m currently at work but want to get to it after my shift.

Hope to hear from you guys and thanks for the advice.
 

AeroCoupe

lube between the nut and the face. I know my lubes
Founding Member
Oct 28, 2001
5,937
4,050
183
Claremore, OK
Jun 28, 2024
#2
  • Jun 28, 2024
  • #2
No vacuum line on my 93.
 
Reactions: keel

Mustang5L5

That is…until I whipped out my Bissell
Mod Dude
Feb 18, 2001
43,264
17,952
224
Massachusetts
Jun 28, 2024
#3
  • Jun 28, 2024
  • #3
You are correct. No line. Remove and cap the other end wherever it comes out from
 

Mcmahst

5 Year Member
Jan 19, 2021
686
270
83
Laguna Woods CA, fort Mohave AZ
Jun 28, 2024
#4
  • Jun 28, 2024
  • #4
Do that, drive it around, and then, pull the codes again.
 

General karthief

wonder how much it would cost to ship you a pair
20+ Year Stangneter
Aug 25, 2016
27,951
10,590
203
polk county florida
Jun 28, 2024
#5
  • Jun 28, 2024
  • #5
It is stock and the MAF is still installed correct?
if yes than that is BAP sensor and no vacuum line.
 

General karthief

wonder how much it would cost to ship you a pair
20+ Year Stangneter
Aug 25, 2016
27,951
10,590
203
polk county florida
Jun 28, 2024
#6
  • Jun 28, 2024
  • #6
It is stock and the MAF is still installed correct?
if yes than that is BAP sensor and no vacuum line.
 
T

t1_5.0

Member
May 6, 2024
18
2
13
California
Jun 28, 2024
#7
  • Jun 28, 2024
  • #7
Mustang5L5 said:
You are correct. No line. Remove and cap the other end wherever it comes out from
Click to expand...
Mcmahst said:
Do that, drive it around, and then, pull the codes again.
Click to expand...
I’ll give it a shot.
 
T

t1_5.0

Member
May 6, 2024
18
2
13
California
Jun 28, 2024
#8
  • Jun 28, 2024
  • #8
General karthief said:
It is stock and the MAF is still installed correct?
if yes than that is BAP sensor and no vacuum line.
Click to expand...
Correct, it has a CAI but yeah stock and still has MAF
 
Reactions: General karthief
T

t1_5.0

Member
May 6, 2024
18
2
13
California
Jun 28, 2024
#9
  • Jun 28, 2024
  • #9
Mustang5L5 said:
You are correct. No line. Remove and cap the other end wherever it comes out from
Click to expand...
I gave it a shot and it automatically idled better. No idea why the previous owner hooked up a vacuum line to it. Either way I have a new sensor so I’ll replace it and hope it clears the BAP code and move on to the ACT code.
 
Reactions: Mcmahst

AeroCoupe

lube between the nut and the face. I know my lubes
Founding Member
Oct 28, 2001
5,937
4,050
183
Claremore, OK
Jun 28, 2024
#10
  • Jun 28, 2024
  • #10
Clear the ECU first and drive it around until up to operating temp. Pull codes again and see what you get. Don’t swap parts just to swap them.
 
Reactions: Noobz347

CAMTWO1070

Active Member
Dec 17, 2021
241
82
38
NY
Jun 29, 2024
#11
  • Jun 29, 2024
  • #11
t1_5.0 said:
What’s up everyone!

My 93 GT is currently getting codes 22 and 54. Being in CA won’t pass smog with a CEL so I’m trying to get these fixed asap.
I ordered and ACT and a BAP in hopes that it’s as easy as old sensors gone bad. My question is my BAP has a vacuum line attached to it as far as I know it shouldn’t. It should be open to atmosphere and plugged at the vacuum manifold correct? Could this possibly be a cause? Also the car does have an erratic idle until it stalls out especially before it warms up. I’ve read that a bad reading from BAP could cause those symptoms.

Again it’s a 93 GT with a C3W. I’m currently at work but want to get to it after my shift.

Hope to hear from you guys and thanks for the advice.
Click to expand...
When you add a vacuum line to a BAP it becomes a MAP and a MAP is needed for Speed Density batch fire vehicles...



BAP stands for Barometric Atmospheric Pressure which is positive pressure and MAP stands for Manifold Absolute Pressure which is negative pressure.

Just like how a weather station measures Barometric Atomospheric Pressure that lil black box is basically a small weather station under your hood..

When the BAP is high near or above 30 the day will be clear and sunny when the BAP is low near 25-26 prepare for inclimate weather..

If you have a Mass Air Flow Sensor in your intake tube you shouldnt have any vacuum line attached to the BAP and is a sign the vehicle may be a MAF sensor retrofit job so Id pull the ECU out and with a multimeter and a diagram do a continuity test on all the circuits looking for a short or improperly installed breakout box for the MAF wires...

Id also do a smoke test with a smoke tester......The smoke tester will reveal any and all vacuum leaks...Even an excessively worn PCV valve can allow too much air to pass through the system and throw things off so dont get thrown off by the fact it still rattles or rattles after cleaning because it may be non compliant..

On the California emission Mustang I bought a few years back it had an 8LD computer which is very very strict on the tune but those MAF retrofit kits they sold used an A9S/A9M computer which will cause you to possibly never pass smog if everything including the lil doohickie on the EGR isnt working properly or the diaphragm is leaking vacuum also your fuel injector pattern flow needs to be good....

8LD vs A9L



What I do is remove all my 02 sensors and dip the tips in Lemon Juice until all the carbon is gone which takes maybe 20 minutes then I rinse with rubbing alcohol and let dry out......The same method works for sparkplugs too but may need a follow up with a wirebrush. or a toothbrush...

All the lil things add up big when it comes to the overall running condition when it comes to a smog exam..





I remove the injectors pull the screen baskets out with a screw and soak them in a mixture of Mineral spirits and transmission fluid and buzz them with a fuel injector tester tool while submerged and after they all pan out flow wise using cleaner and a can adapter for fuel injectors I reinstall them rest assured theyre good or you can buy a new set of 19lb injectors off of ebay for like $30 bux for 8 versing paying $25 for the o-rings , pintlecaps and basket screen kit and actually save yourself some money.





Having one of these $8 wires from ebay and an OBD2 handheld is an awesome thing to have when you can read the engine stats as it runs and know what sensors dont comply...



Good Luck

 

Attachments

  • IMG_20211212_185022.webp
    328.2 KB · Views: 119
  • IMG_20230422_124732.webp
    287.8 KB · Views: 112
Last edited: Jun 29, 2024
T

t1_5.0

Member
May 6, 2024
18
2
13
California
Jul 9, 2024
#12
  • Jul 9, 2024
  • #12
Well it took my a while to get it done busy with work. Code 22 cleared after removing the vacuum line and plugging the other end.
Thank you guys for the tips!

Now I just have to deal with code 54 which is the intake air charge temp sensor out of range or circuit on. I have the sensor which I can replace but does anyone have any other tips? Maybe something that worked in the past ?

Thanks again guys!
 

Attachments

  • image.webp
    284.3 KB · Views: 124

Mustang5L5

That is…until I whipped out my Bissell
Mod Dude
Feb 18, 2001
43,264
17,952
224
Massachusetts
Jul 10, 2024
#13
  • Jul 10, 2024
  • #13
Before you parts swap (which you can certainly do if you don't care about the $$), i'd test the ACT sensor itself and the wiring. Code 54 means that either the sensor is broken and open, or the wiring is broken and open.

To test the sensor, unplug it and measure the resistance across the terminals. If the engine is cold, the sensor should read ambient temp, which is somewhere in here
50 degrees F = 58.75 K ohms
68 degrees F = 37.30 K ohms
86 degrees F = 27.27 K ohms
104 degrees F = 16.15 K ohms

If you get what you expect, the sensor is fine. Move onto the wiring.



IAT in 1993 should have a gray/red wire and a gray wire. The gray/red is ground and connects (off-page) to sensor ground which is pin 46. If you measure voltage to ground on the pin 25 wire (gray) you should have voltage there. I think it's 5V but you should read voltage to ground. Or, you can turn the car off and just test continuity from that wire to pin 25. That indicates the circuit is connected to the ECU. The other wire should have continuity to ground.
 
Last edited: Jul 10, 2024
Reactions: General karthief
You must log in or register to reply here.

Similar threads

Mustang II 4 cyl gear hunting and possibly messed up vacuum system
  • oesterreicher
  • May 31, 2026
  • 1974 - 1978 Mustang II Talk & Tech
Replies
11
Views
316
1974 - 1978 Mustang II Talk & Tech Jun 14, 2026
manicmechanic007
Engine Random Misfire at idle.
  • Gulftown980x
  • Jul 29, 2026
  • SN95 4.6L Mustang Tech
Replies
11
Views
227
SN95 4.6L Mustang Tech Jul 31, 2026
squeak93
Vacuum line question?
  • Mustang Momma
  • Feb 10, 2026
  • 1996 - 2004 SN95 Mustang -General/Talk-
Replies
1
Views
173
1996 - 2004 SN95 Mustang -General/Talk- Mar 3, 2026
Noobz347
Fox Fuel Pump Issues After Replacement/Upgrade
  • Ryu
  • Jun 23, 2026
  • 1979 - 1995 (Fox, SN95.0, & 2.3L) -General/Talk-
  • 2
Replies
23
Views
607
1979 - 1995 (Fox, SN95.0, & 2.3L) -General/Talk- Jul 5, 2026
Ryu
B
Electrical Why does my fox body keep frying eecs
  • brandyn200
  • Jun 20, 2026
  • Fox 5.0 Mustang Tech
Replies
8
Views
281
Fox 5.0 Mustang Tech Jun 25, 2026
AeroCoupe
Share:
Bluesky Email Share Link
  • Mustang Forums
  • 1979 - 1995 (Fox, SN95.0, & 2.3L) -General/Talk-
Menu
Log in

Register

  • Forums
  • What's new
  • Media
  • Resources
  • Contact
  • Sponsor
X

Privacy & Transparency

We use cookies and similar technologies for the following purposes:

  • Personalized ads and content
  • Content measurement and audience insights

Do you accept cookies and these technologies?

X

Privacy & Transparency

We use cookies and similar technologies for the following purposes:

  • Personalized ads and content
  • Content measurement and audience insights

Do you accept cookies and these technologies?