: 2001 Cadillac DTS Can't get up to speed, power loss, studdering, See Video

09-30-09, 01:44 PM
My DTS had started to run bad and eventually was getting horrible gas mileage. After some research I found out that it was the Plenum, so I picked it up at my local Caddie dealer and was ready to replace it.

My wife was on her way home and she said she couldn't get up to speed and the car would just die out, she said that she couldn't get it past 20 mph as if the traction was on or it was starving for fuel. I used my code scanner when she got home and found a Intake and a loss of memory code, I don't exactly remember what they were because before I went on the 1st drive after replacing the Plenum I erased the codes. I took it for a ride after replacing the Plenum and it has the same issue and no codes?

Any Ideas?

Thanks any help would be greatly appreciated,

Here is a Video

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09-30-09, 03:58 PM
Instead of using the hand scanner, use the car's built-in code system and reader. Study the entire sticky thread at the top of the main Deville page titled "How to pull codes", use the link to the site with "obd2" (OnBoard Diagnostics protocol - OBD-II) in the URL. Practice. Write down all the stored codes, noting whether they are Current or History. Then return to the site to get the meanings of the P,B,C, and U codes. Do not "clear codes" yet. Come back here.

That idling engine should be absolutely dead quiet.

I believe I hear a massive vacuum leak - near the passenger end of the intake. Is the PCV system hooked up correctly, the manifold bolts torqued to 7 ft/lb (89 in/lb), did you check the manifold overpressure valve (passenger end recess) for seal, how about the integrity and alignment of the intake ducting and MAF, the vacuum lines at the throttlebody connectors ?

EDIT at 4:23: Watching your other questions brings up the cat thing........Do you have any reason to believe that the cat is suddenly plugged, as from operation with too rich a fuel mixture or some other foreign substance ? Midrange power losses are sometimes cat-related.

This one's a brain teaser........

09-30-09, 08:21 PM
Wow! Thats Great!

I pulled Loads of History codes, but only one current IPM B0429

Fuel Pump?

Thanks :)

09-30-09, 08:35 PM
B0429 is an Actuator :-(

Here is the History, what do you think?

DIM B1327
DIM B2810
DIM P1531
DIM U1300
DIM U1301
IPM B0429
IPM B1004
IRC B1327
IRC U1064
IRC U1016
MSM B1860
RFA B1327
TTM B1396
TTM B2891
TTM B2862
TTM B1328
TTM B1327
TTM B2862
TTM B2860
TTM B2882
TTM B2880


09-30-09, 08:40 PM
The cat could be clogged, but when the plenum went my wife drove it for 4/5 days while it was running lean...Could that have toasted the cat?

BTW I just replaced the Battery(B1327) and Blower Motor.


09-30-09, 08:53 PM
The lean codes/fuel ratios from a cracked plenum should not toast the cat. Most cat problems come from either rich fuel mixtures or attempts at burning various solvents and engine cleaner mixtures.

Go back to the code thread and decipher all those B codes (body control codes) and the P1531. (If all the codes are History, then something is fishy. With your symptoms, one or more are Current.)

09-30-09, 09:12 PM
You have a great point...Since there are no current real codes, could it be the Fuel Pump, should I test the pressure?

P1531 - A/C Low Side Temperature Sensor Fault

B1327 - Vehicle system voltage below 9.0 volts
B2810 - Steering wheel controls Entertainment Circuit Malfunction
B1004 - Keep Alive Memory (KAM)
B1396 - Device Voltage Reference Output 1 Circuit Range Performance
B2891 - Tilt/Telescope Motor Over Current
B2862 - Telescope Position Sensor Low
B1328 - RH Sun Load Sensor Fault
B0429 - Temperature Control #3 Rear Circuit Range/Performance
B2882 - Tilt Position Sensor Low
U1300 - Class 2 Short to Ground, When I jumped it I arched the cable :shhh:
U1301 - Class 2 Short to Battery
U1064 - Loss of Communications with DIM
U1016 - Loss of Class 2 Communication with VCM

Doesn't sound like codes that would make the car run so bad?


09-30-09, 09:29 PM
B1327 - Vehicle system voltage below 9.0 volts

U1300 - Class 2 Short to Ground, When I jumped it I arched the cable :shhh:

Get the charging system tested, you may be on the last leg of your alternator... Unless you have another reason for these codes and having to jump start it...

09-30-09, 09:51 PM
Clear all those codes and see what returns.

09-30-09, 10:17 PM
The positive terminal was dangling from my old battery, I replaced it with a new one last Friday...Also while jumping it I arched one of the cables....That has to be those codes right?


09-30-09, 10:44 PM

10-02-09, 04:46 PM
Do you think it could be the cat?


10-02-09, 05:18 PM
If the CAT is plugged you will see drivability problems at high RPM's (highway or WOT). Like trying to exhale while pinching your nose.

10-02-09, 06:23 PM
Try checking the fuel pressure...

10-03-09, 06:11 AM
Low fuel pressure or faulty coil cassettes.

Look out for a glowing red cat converter after trying to drive like this. Try driving like this at night, keep it floored a bit and check under the car. If you see ANY signs of the cat beginning to turn red, stop the car and let it cool down. Don't go far from home. 2 miles should tell you.

I have seen this quite a few times and failing coils will cause exactly what you're experiencing. Low fuel pressure will sometimes throw a lean code but will also limit your speed.

I agree with Submariner409 - sounds like a big vacuum leak. Hard to tell from a video though, could be one of your pulleys or accessories. If it's a vacuum leak, that could be largely the problem as well. Take Krashed989's advice and check that and the fuel pressure before replacing coil cassettes.

10-03-09, 08:15 PM
Definitely a clogged cat or low fuel pressure. If there is too much backpressure in the exhaust it messes with the mass air flow sensor since it sees the TPS sensor at 100% but a low amount of air volume coming through the MAF.


10-16-09, 08:07 AM
I just wanted to follor up....It was a clogged catalytic converter, runs better then ever now..