Misfiring In 1 And 6 / Brownish Coolant

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Hey all,
New to the group....Been driving the Catera quite hard lately, and the next thing I know, the CEL pops on and she starts shakin like crazy. Took her to the shop (not dealer) and they ran the codes saying that she is misfiring in cylinders 1 and 6. He suggested getting new spark plugs and wires all the way around. Does anyone have any idea how much this would cost, or if there is any chance I could do it myself. I've heard that Catera's have Coil On Plug (COP) ignition systems....would this make the task more difficult/what exactly is COP? Also, I refilled the slowly leaking coolant the other day, now the coolant looks a dark brown? P.S. Here are some links to pictures I took today....I'm not quite sure what it is im looking at, anyone know?
Thanks all



posted by  catera1997

The spark plugs should cost you around $10. The wires between $20-$35

As for the picture, not sure. Try not taking pictures so close up next time? :banghead:

posted by  DodgeRida67

looks to me like lube oil instead of anti-freeze. I obviously have to see the car to know exactly what I am looking at.

If you do it yourself, spark plugs for a Cadillac Catera are platinums and will run $2.50 each for single platinums, about $3.50 ea for double platinums

The 1999 Catera has plug wires which are pricey. You are holding a plug wire in the picture

2000 and later has Coil on Plug ignition.

You either need to find a shop manual and get specs for the car or if you don't own tools or aren't comfortable working around the car, find a good shop.

either way you decide, I would do the following (assuming the car has 70K - 100K miles on it)

1. replace the plugs. gap specs are 0.040 inch

2. Use a calibrated ignition tester and (one wire @ a time) connect the tester to each plug wire crank the engine and ensure the ignition system is delivering adequate voltage to spark. If it sparks, we make sure the fuel injection system is working (come back and we will discuss), no spark or low voltage, we go to step 3

3. Use an ohm-meter to test each plug wire, starting with any wires which indicate low or no voltage. You are looking for 4000 ohm/ft (15000 ohm maxumum resistance) If the wire is broken (open circuit) or if the resistance is too high, replace the wire. Look @ the insulation. If you see cracks, wear, or other signs of aging or deterioration, replace the wires ($170 @ NAPA).

if the plug wires are good or have been replaced, check the primary and secondary resistance of the coil packs. If the coil packs are OK, clear the codes with a code scanner and see if the problem is fixed. If it is not, come back and we will discuss ignition systems in depth

Vacume leaks @ the #1 and #6 cylinders (i.e. bad fuel injector O-rings, etc.) will also cause misfire

If you suspect coolant leaking into the block, have a compression test done

posted by  tbaxleyjr

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