: 99 Cat hesitates on accel.; idles rough

03-26-08, 08:20 AM
I have a 1999 Catera Sport. A few days ago it started idling really rough, and would hardly accelarate without feeling like the car was going to shake itself apart. Had it scanned at the local A-Zone. It flashed a P0301(misfire, number 1 cylinder), P1530 (either a throttle actuator contorl or Ignition timing adjust switch (crankcase position sensor??)), and a P1511 (Throttle control system-throttle blade motor to the limp home throttle angle).

So, I pull the pass. side coil pack; sure enough, there is a little oil in all three plug holes (valve cover gaskets replaced about 2 months ago), and the number 1 boot is cracked in two, with apparent arcing from the wire to the head (discoloration on the boot, looks kind of grayish). So, I call the same parts store, they say they have the spark plug wires in stock, around $170. Another trip to the store, but what their computer lists as plug wires for a 99 Catera were actual plug wires. About 2 to 3 feet long, not the short boots that go from the coil pack to the plug. So, I order two new coil packs, which after looking at the computer screen I see have the boots attached. About $100 a side. Figured I would go ahead and get the driver's side as well, for when I feel like changing that.

Parts will be in tomorrow, we will see if that fixes the misfire on number 1, which I am sure it will. Now, to figure out what is up with the other 2 codes. Apparently either sticking throttle, or maybe TPS going bad? And may go ahead and replace CPS, just to be on the safe side. Anybody else ever had a P1530 or P1511 flash?

Thanks to everyone on this forum who have posted about similar problems with their cars. Hopefully these fixes can help out somebody else with similar issues.

Gotta love these cars. Right???!!!!!!!!!!!


Po Pimp
03-27-08, 02:00 AM
Any luck?

Sorry I really have no experience with either of those codes.

03-27-08, 09:57 AM
I will be picking up the coil packs today; will see if that fixes the acceleration issue.

I read somewhere on here that someone had one the these codes after leaving their key in the "on" position for a couple of minutes. I guess the system sees the ignition on, but the throttle body closed, so it throws a code.
Come to think of it, last time I took the car to the car wash, they had left the key in the "on" position while they were cleaning the inside, apparently listening to the radio or something. If I remember correctly, the CEL came on shortly after that. Probably unrelated to the misfire problem. Going to disconnect the battery, maybe that will clear the other two codes (If only I could be so lucky).

Po Pimp
03-27-08, 09:33 PM
Remember after you disconnect the battery that the key sshould go into the run position for 3 minutes. This will tell the computer to relearn the idle.

03-28-08, 09:18 AM
Thanks for the heads up on the battery disconnect. I replaced the battery about a year and a half ago, and don't recall doing that.

So, I changed out the 1-3-5 coil pack last night, went ahead and put new plugs in as well, as they were just about due to be replaced. Didn't disconnect the battery yet, as I wanted to see if the coil pack replacement affected the poor running issue. Sure enough, car cranked up and idled perfectly. Went for a spin around the block, and no hesitating at all.

I had forgotten how good this car drives when it is running right (not my daily driver, my girl drives it now since I bought the Jeep).
CEL still on; going to see if it cycles off on it's own. Probably going to have it scanned again after a couple of days if it stays on to see what codes are flashing.

So, it appears the the rough idle and hesitating were due to the broken plug wire. Guess it was arcing to the head and causing the problems. Going to check 2-4-6 coil pack this weekend, and probably go ahead and replace CPS also. I don't think they are necessary, but I have the parts so going to go ahead and replace.

If your Cat ever idles really bad, almost to the point of stalling; and it feels like it is going to shake itself apart when you hit the gas, you may want to check your plug wires. This seemed to have fixed my problem (knock on wood). Hopefully we can get another 112,000 miles out of this car without any other issues (I know. But I can dream, right?)