Slow/Sluggish Acceleration, Periodic Chugging

[WLSquire]

I have a 2002 Saturn SL1, 180k Miles. It's my first car. I'm no master mechanic, but i know a bit about cars. Mainly basic regular maintenance. I recently did a fair amount of work on it because it sat for almost a year in my dad's front yard. The work included:

Steering Column Replacement
Security Bypass ("Re-Learn")
Tire Rotation
Oil and Filter Change
Brake Bleeding and Fluid Top Off
Exhaust Repair

After all of these things were done, i started her up and took her for a test drive. The issue that arose, was that my car accelerates painfully slow, even with the accelerator all the way to the floor, and sometimes chugs and lurches. I tried letting the car warm up a little before driving it, i tried shifting through all the gears and letting it idle while in each gear, and it's doing the same thing. Only once or twice has it actually accelerated at a normal rate, but then it chugs and begins to accelerate really slow again. My brother, my dad, and myself all came up with the following possible diagnoses:

-Bad/Faulty Fuel Pump

-Poor Fuel Pressure

-Not enough air getting to the engine (The engine cant breathe)

-Throttle Position Sensor

-Bad Timing Belt

-It's just old, and sat for too long, and needs to be driven for a while to get used to being "alive" again.

If anyone has any possible answers to why my car is doing this, PLEASE HELP. I just want to be able to drive my car and not have any significant problems.

[fdryer]

WLSquire, many new members mistakenly post in the wrong forums. Your car is an S-series and this is the L-series tech forums. Simply let this post die on its own and copy and paste your post into the S-series tech forums. You're likely to receive more replies from fellow S-series owners.

In the meantime, consider a few suggestions.

1-A fuel pressure gauge removes all doubt when used. Autozone may have a loaner. Expect between 40-55 psi. If the fuel filter was never replaced (every 100k miles), replace it and re-check pressures.

2-At 180k miles, nothing lasts forever. A damaged catalytic converter can occur at any time. The ceramic substrate is built as brick honeycombs to allow exhaust gases to pass thru while reacting to platinum. Two ways to check for damage. 1-Damaged, disintegrating catcons fall apart internally and may rattle when banged by hand. 2-Remove the upstream O2 sensor to allow exhaust to exit upstream the suspected clogged/partially blocked catcon. If the engine suddenly shows renewed power, the catcon is blocking exhaust flow. A brief drive around the block can verify this but exhaust may need a diverter to prevent hot exhaust gases from burning nearby parts. Soup can sheet metal can be formed to help divert hot gases away from nearby plastic.

[JohnSC]

Originally Posted by fdryer

WLSquire, many new members mistakenly post in the wrong forums. Your car is an S-series and this is the L-series tech forums. Simply let this post die on its own and copy and paste your post into the S-series tech forums. You're likely to receive more replies from fellow S-series owners.

In the meantime, consider a few suggestions.

1-A fuel pressure gauge removes all doubt when used. Autozone may have a loaner. Expect between 40-55 psi. If the fuel filter was never replaced (every 100k miles), replace it and re-check pressures.

2-At 180k miles, nothing lasts forever. A damaged catalytic converter can occur at any time. The ceramic substrate is built as brick honeycombs to allow exhaust gases to pass thru while reacting to platinum. Two ways to check for damage. 1-Damaged, disintegrating catcons fall apart internally and may rattle when banged by hand. 2-Remove the upstream O2 sensor to allow exhaust to exit upstream the suspected clogged/partially blocked catcon. If the engine suddenly shows renewed power, the catcon is blocking exhaust flow. A brief drive around the block can verify this but exhaust may need a diverter to prevent hot exhaust gases from burning nearby parts. Soup can sheet metal can be formed to help divert hot gases away from nearby plastic.

Will knocking the guts out of the Cat eliminate this problem? If so then how will it effect the computer? Will it throw any codes?

[fdryer]

JohnSC, the answer is a double edged one. Yes, a blocked exhaust system from a catcon with loose cat guts rattling around, large pieces blocking exhaust flow to create an engine with zero power, can be gutted to restore full power again. This presumes you're in a state without emissions inspections. Some here have done this while others simply cut off the catcon and run a plain pipe in place, welded or clamped. With or without a catcon, the engine will run fine but the downstream O2 sensor will cause an error code. Some have found extenders (threaded bushings to put the sensor further away from the exhaust stream to eliminate this error code. The second O2 sensor measures catcon efficiency and does not influence the EFI system. The first O2 sensor, before the catcon, does monitor exhaust and has a direct influence on engine running, the basis for all gasoline cars in the USA to adhere to EPA emissions. Every USA vehicle with OBD I or II have programmed EFI systems to control emissions with the upstream O2 sensor continually adjusting fuel mixtures. The downstream sensor measures the catcon and tells the engine computer whether or not to turn on the cel for catcon issues.