I'm still working on getting all the bugs out of the DonKo. I finally got a Check Engine Light (CEL). The engine had just gone 177 miles of highway travel at speed on a beautiful but Hot Montana day, about 85 degrees, and I pulled over to check the tires. When I tried to get going again it wouldn't accelerate. It's like there's no "give it some gas" control. I have to quickly pump the gas to get any acceleration at all. So I sit there letting it cool off.

This happens while I'm going up one of the mountains that Montana is famous for. So I'm going up in the breakdown lane, just barely make it over the top and let it coast on down the other side. By then it's cooled off enough to hobble into the driveway.

I got the codes from O'Reily's borrowed code reader. It's OBD I.
KOEO was pass with 11
The Continuous Memory held, 41 and 32, twice because the CEL came on twice.
The KOER was 25.

So I'm thinking replace the Oxygen sensor.

My question is would a defective oxygen sensor cause the symptoms described or is it a blown head gasket?

 

Code 41, HEGO was lean. Indicates more oxygen in the exhaust than the O2 sensor was expecting to see. Can be caused by a number of things but most often a vacuum leak.

Code 32, EGR valve not seated. Indicates the EVP did not sense a full closed position on the EGR valve. Dirt, soot, carbon build up at the pintle on the valve will cause this.

Note that the condition of the EGR valve not fully closing (Code 32) can cause the lean condition that triggered Code 41.

Code 25 indicates the knock sensor (KS) did not detect detonation during operation or during the KOER test. To check the KS, with the engine running and warm, give the block a few sharp taps with a hammer. You should hear the rpms drop as the PCM retards the timing to compensate. If not, the KS has either come disconnected or has failed. This is the most likely culprit for your problems since detonation on long hill climbs is not uncommon. With no detonation information, the PCM has no idea that its happening and you lose power.

 

Replaced the fuel pump with a Ford new pump.

Bronco works good now.