2000 Bravada, approx 90,000 miles. Very sluggish acceleration, started out as an intermittent issue, but last day or 2 it's been constant. To the point now where I have to hold it to the floor to maintain 40mph on a flat road. Also, it wont hold a constant RPM under constant throttle - it's a cycle of cutting off and surging. Another thing I noticed, which may or may not mean anything - above 5000 rpm, the volt gauge drops quite a bit and the AC stops running cold.

Ran the codes, and got the following:
P0101
P0131
P0143
P0151
P0300

Researched the codes and it appears it could be a myriad of issues from plugs/wires, to O2 and airflow sensors.

Any input as to the most likely culprit(s) will be greatly appreciated.

Thank you!

 

how long ago did you do a tune up on your truck? did you use ac delco parts?

 

Bought it 3 years ago with 60,000 miles - a tune up was a condition of the sale, but I do not know what brand parts were used.

 

P0101 - Mass Air Flow System Performance
P0131 - HO2S Circuit Low Voltage Bank 1 Sensor 1
P0143 - HO2S Circuit Low Voltage Bank 1 Sensor 3
P0151 - HO2S Circuit Low Voltage Bank 2 Sensor 1
P030x - Random/Multiple Cylinder Misfire Detected

I would look into the power & ground supply for the HO2S sensors from the PCM as defined in the wiring diagrams in the linked to diagnostic threads. A PCM ground issue could cause the MAF & HO2S sensor codes and general poor performance. Look over the diagnostic threads for common diagnostic points.

 

i say do a decent tune up check the whole truck over make sure you use delco parts . let us know if that helped it run better

 

Thank you. I sort of figured that 3 O2 sensors throwing codes simultaneously was probably caused by something other than the sensors themselves. Unfortunately, electrical diagnostics and me don't get along very well - might be time to bite the bullet and take it to someone with the tools and patience to track it down. Before I do take it in, is there anything glaringly obvious I should take a look at?

 

Researched on here and found that the PCM is grounded to the firewall by the brake booster (G117). Checked that out and it's tight and clean as a whistle.

Anything else easy to check before I wave the surrender flag?