Flr Power

A good ground should be below 2 ohms.

raverx3m

iTrader: (1)

i rechecked again
that wasn't the ground
that wire goes to fuse box and then ignition and is good

the diagram online is kinda retarded all the pins are mixed up for main relay

the ground from main relay to the ecu is good
ground from ecu to thermostat is good
injector to ecu wires are good
injector grounds are good
injector impedance is good
all distributor wires are good inside and to the ecu
rear O2 wire to ecu is good
heater and signal
will have to check the primary o2 heater ground
the primary o2 signal to ecu is good
primary o2 voltage between pin 3 and 4 is good


my main suspect is the primary o2 heater ground
i had to navigate through wrong year service manual... have to ckeck tomorrow again

i would assume that will cause the rest of the issues
sluggish low throttle low rpm acceleration due to lean spot because of incorrect reading from primary o2 sensor which in turn will heat up the cat too much and trip the secondary o2 sensor for low cat efficiency
and probably by now damaged the primary sensor..
am i thinking correctly?

PyroProblem

7.6 ohms i close enough to zero, that I don't think it should affect anything.

How quickly do these codes return?
Can you graph the secondary o2 sensor voltage? Or just see the voltage values?

raverx3m

iTrader: (1)

scan gauge updates every 2 seconds its not a great datalogging tool lol
i need to get a datalogging butplug for it. from ebay or something and see the graphs


after i cleaned corroded grounds codes were gone for over a week

now they are popping up every few days.

the secondary o2 had damaged and exposed wires. who knows how long they were like that.
the green and white wires were damaged. and covered in oil and probably water.
i don't know if that can damage the ecu circuit

PyroProblem

Yeah 2 seconds isnt fast enough. Ever tried tht app Torque? I use it on my other vehicle and its pretty cheap and effective. Only works on obd2 vehicles. The bluetooth adapter is like 10 bucks.

The ECU is fused so I ASSUME any shorted circuits on the output side should pop the fuse before it damages the ECU. As long as you don't put unfused power directly to the ECU, I think your OK.

I retract my comment about 7 ohms probably being acceptable. The lower the better of course and in a perfect world it would be zero, but some resistance is always present.

After you reset the fault and the fuel trims zero out, can you watch the long and short term fuel trims?

raverx3m

iTrader: (1)

Hooked it up to a pro scanner and both sensors seem to be working good
The downstream wave follows the upstream with slight delay
Both heater circuits show on
All other sensor reading seem to be ok

found a crack in my header #4 right at the flange which is fresh
Welded that up

Replaced the guts in the distributor the insulation on the magnetic pickups was cracked
And threw 0161 0162 codes for tdc sensor when i moved the wires
It seems to be driving much better now

Could have been the distributor issue
Will see how it goes

PyroProblem

The down stream should flat line around .6 volts for the most part. This indicates a correctly functioning cat. If after your exhaust leak is fixed, and the signal still follows the primary o2 sensor, your p0420 code will likely return.
Hopefully the p0133 slow response fault goes away too.

PyroProblem

Kinda explains why it would happen in the lower gears only with the engine probably moving a bit more, making the exhaust leak worse and then the ECU is probably dumping fuel in from the false lean signal, causing the driveability issues. Good luck.

raverx3m

iTrader: (1)

so far no codes
car runs better it was definitely faulty wire in the distributor.

but I can still feel the lean spot from about 2000 to 3000 rpm in low throttle

still have no fn clue why its there when I checked and rechecked everything already

PyroProblem

I don't see how a faulty wire in the distributor could cause an o2 sensor fault but hey as long as it's working!

Shouiee Yang

Darn it. I really hoped that you figured out what the problem was because I am having the exact same issue. Stupid o2 and that loss of power at 2000-3000 rpm in 1st and 2nd gear 😭