Safe workaround?

Maintenance/Repairs
1

Somewhat long story here . . . I’m hoping this unorthodox repair is ok for an old car that simply gets me back and forth to the commuter lot every day.

2001 Saturn SL1. CEL came on with a code for the secondary air injection system. Found proper voltage at the air injection pump, but the pump wasn’t working. The rest of the system checked out ok. Got a pump from a junkyard (they don’t make them new anymore). Same problem with the “new” pump. Figured bad luck and bad part. Sourced another junkyard one. Same problem with this “new” pump.

Did some research and saw someone had fixed a similar issue by cleaning the pump’s ground wire connection. I found the point where the ground wire attaches to the frame. There are 5 wires grounded here. There was a plastic cover housing those connections. Inside was a thin copper plate, maybe three inches long and thick as cardstock (think business card paper), with prongs for wire connectors. The plate itself looked fine, but all the wire connectors were corroded – I mean green like the Statue of Liberty.

In the interest of not spending hours trying to match gauges for 5 different wires and connectors, I took a shortcut. I cut the wires before the connectors; stripped the ends; spliced them all together with a single, small length of 10-gauge household wire; stripped the other end of the 10-gauge wire and wrapped it around the copper plate; wrapped some electrical tape around that; and screwed the plate back to the frame. I couldn’t reuse the plastic cover, as I had to cut it open to remove it.

I’ve driven over 100 miles since and no CEL anymore.

Is the 10-gauge household wire without the plastic cover a safe fix for the long term? A 10-gauge household wire is rated for 24 amps at 120 volts, or 2880 watts. I can’t think of any combination of things on a car (other than the battery) that could produce anywhere near 2880 watts. All the wires that I spliced were quite narrow – nothing approaching the thickness of a household wire. So, I’m guessing a 10-gauge ground connection isn’t going to be any issue.

But, absolutely, please correct me if I’m wrong.

In any case, I am the now the proud owner of an 18 year-old car that will pass state emissions inspection, along with two backup air injection pumps. Anybody need a spare?

2

The gauge of the wire is dependent on the length when sizing for current.

So for example, I had to run 10 gauge wire from my fuse box 60 feet to to my 2 H.P. 220 volt compressor for the proper wire size for the current over that distance.

For what you did?

You’re good to go.

Tester

2 Likes
3

If it works guess you did ok, My big concern would be the electrical tape trapping moistre and corroding the connection and wire. Solder would help, also some of the black rubber like sealant for electrical connections might be good. Drive on.

1 Like
4

It may not be clear but it appears you said you just wrapped the new wire around the plate and covered with tape. It needs to be soldered to the plate, crimped onto it or squeezed between the plate and ground. Just wrapping it will fail pretty quickly…

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5

First, the problem was never the pump. Your original pump works just fine. The problem is where the air enters the exhaust manifold.

During the first two minutes after a cold start up, the pump is activated. It sends air through a rubber tube to a reed valve. Sometimes during high humidity freezing weather, the reed valve will ice up and give you the DTC for secondary air, but this is not the time of the year for that.

From the reed valve, the air goes to the exhaust manifold through a metal tube IIRC. You need to remove this tube and take a wire probe, like that 10 Ga wire you want to use and probe it down into the manifold at least an inch, maybe more. Also use some carburetor cleaner spray to clean out this passage. If you get spray back from the spray cleaner, you need to probe deeper.

Once this passage is cleared, the code will go away. BTW, the DTC is NOT monitoring the pump. It is monitoring the catalytic converter. During the first two minutes after a cold start, the fuel injection is running the engine too rich for the cat to work. The extra air in the exhaust provides the O2 needed to “light off” the cat and get it working. If it sees cat efficiency too low during the first two minutes, it sets the DTC for secondary air instead of the usual P0420 code. If it sees it after the two minute mark, then it sets the P0420 code.