02 Buick Lesabre Custom occasional hard start, backfires occasionally, manifold exploded

02 Buick Lesabre Custom occasional hard start, backfires occasionally, manifold exploded put out fire fast

not making sense here
first off car showed no codes at all
then code P0171 and P0171 pending kept showing so replaced a few things that thought was code related
then codes show up then boom intake manifold explodes lucky put out fire fast

P1689 BUICK Code - Traction Control Delivered Torque Output Circuit
P1575 BUICK Code what is this? location of where to look for ? Extended Travel Brake Switch Circuit ?
P1133 BUICK Code O2 Sensor
P0171 Buick Code
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All I have Replaced ----
Oxygen (O2) Sensors
Fuel Injector Connector
Intake Manifold
Fuel Line / Hose
Fuel Injectors
Spark Plugs and wires
Air Intake / Charge Temperature Sensor
MAF Sensor
new Fuel Rail
also did a smoke test small leak but fixed Fuel Line / Hose replaced

and a couple other things replaced
any ideas what I should look at from here
someone said fuel pressure regulator ? bad O2 sensor even though new ?
Timing Chain
any help at all is deeply appreciated Thanks

The harmonic balancer could have slipped around the hub, also crank and or cam sensor can be be bad. Google the other codes, plenty of info out there.

As Max alluded, the two are related. The crank position sensors (multiple) are behind the balancer on a '92, or at least are from my recollection.

Well sorry for the late response

did a compression test
1 rear cylinder is dead, 1 very week
other 4 are strong


now do I junk it
get a junk yard engine or

get 1 from autozone or advanced discount auto which I really don't care for
figure just had the tranny redone
Thanks for the advice
did put a new camshaft sensor in was going to put the crank shaft sensor in


side note has any one bought a engine from autozone and if so is it worth it and how complete are they


don't think its safe enough to drive with 4 cylinders?

Is the low compression due to bore/ring wear, valves, or something else? It is possible the block and rotating assembly are serviceable and a valve is bent, stuck, or not opening.