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What all sensors on a 5.3 effect the way it runs? (Narrowed it down)
- Thread starter shady
- Start date
Some of these parts have no real defined lifespan. The environment an O2 sensor lives in means it has to be replaced every now and again. A crank or cam position sensor is either a coil of wire or a hall effect sensor and could possibly outlast the vehicle. In the middle are things with a potentiometer, like a TPS. If you can find AC Delco "OEM", those are almost always good parts. AC Delco Professional are usually good, but AC Delco Advantage isn't always better than the cheap brands. In today's supply chain, sometimes working used OEM low mile parts are the best thing you can get.
As for the original question, the only sensors that don't affect how it runs are the downstream O2 sensors and stuff related to evaporative emissions.
As for the original question, the only sensors that don't affect how it runs are the downstream O2 sensors and stuff related to evaporative emissions.
black dawg
1/2 ton status
Have had more wiring issues causing intermittent stuff in those trucks. Other than the throttle stuff, the engine sensors are pretty reliable.
Have also seen a couple times in the last two years, moisture in the ecm connectors...lots of strange intermittent stuff.
Have also seen a couple times in the last two years, moisture in the ecm connectors...lots of strange intermittent stuff.
My last delco fuel pump (hecho in china) lasted about two years. The one prior (hecho in us) lasted about ten years, and I just put it back in to replace the failed chinese unit. I've had two delco oil pressure/switches new in the box fail within 2 years each.
There is a HUGE difference between a part that has proven to be good in daily use, and an off the shelf of unknown quality. I firmly believe GM is not selling the same parts they use in their vehicles when new. The failure rate cannot be this bad.
It also stands to reason that with as many fake parts as the Chinese are making now, anything not bought through someone that can trace the supply chain directly to GM/Delphi(?), may in fact be a fake part. There is almost no way to know, it costs the chinese no more to print a box with delco or Delphi on it as any other logo, and they can laser etch or cast logos and part numbers just as easily.
My IAC, IAT, MAF and ECM are from 1988. Complete distributor lasted about 25 years, as did the injectors. Only reason I swapped other sensors and switches is to go with later parts that simplified wiring or theoretically helped, like a heated O2, or because I didnt get the OEM sensors when I did the injection swap. None I swapped out had failed...but some of the delco parts I purchased and installed later, did.
I'm even leery of keeping new or used spares on the shelf anymore. (But I do because I dont want to have to source them when I need them) I suspect many have things like rubber internally that will degrade over time, no matter how they are stored.
We had a sign in the office at the jumkyard that said :
"Used parts is good parts"..
They were "proven"...
Another quote I've seen at other yards on the wall is "The president's limo is driving around on used parts--so can you !"..
My friend often has resorted to buying "junkyard" sensors when a customer has little cash and cant afford a brand new sensor that's $100+ bucks ,that fits in a box smaller than half of a pack of cigarettes,but need their car to run to get to work ,shop,and get the kids to school..most folks that aren't mechanically inclined think they are being ripped off when the part is so small..
More than once he's gotten sensors that were junk right out of the box from a parts store,and they couldn't get another one in stock the same day--so he went to the junkyard,got a used one,and the car started and ran fine again..
He wont put in used electric fuel pumps though,unless its one you can access thru the car's trunk or under the rear seat--if the tank has to be dropped,its either get a new pump--or bring it elsewhere to have it installed..he's had numerous new pumps fail quickly too,so even insisting on a new one isn't a guarantee he wont be dropping the tank again in a few months..
It sucks now that so many parts are inferior or just plain fake ,you never know what your getting any more--it was bad enough in the 90's when I was a parts counterman,you always held your breath when you sold a customer a part from certain manufacturers that didn't have a real stellar reputation..counterfit parts were a big problem then,I remember some spark plugs we got in boxes that closely resembled AC plugs,but were some third world copy..
"Used parts is good parts"..
They were "proven"...
Another quote I've seen at other yards on the wall is "The president's limo is driving around on used parts--so can you !"..
My friend often has resorted to buying "junkyard" sensors when a customer has little cash and cant afford a brand new sensor that's $100+ bucks ,that fits in a box smaller than half of a pack of cigarettes,but need their car to run to get to work ,shop,and get the kids to school..most folks that aren't mechanically inclined think they are being ripped off when the part is so small..
More than once he's gotten sensors that were junk right out of the box from a parts store,and they couldn't get another one in stock the same day--so he went to the junkyard,got a used one,and the car started and ran fine again..
He wont put in used electric fuel pumps though,unless its one you can access thru the car's trunk or under the rear seat--if the tank has to be dropped,its either get a new pump--or bring it elsewhere to have it installed..he's had numerous new pumps fail quickly too,so even insisting on a new one isn't a guarantee he wont be dropping the tank again in a few months..
It sucks now that so many parts are inferior or just plain fake ,you never know what your getting any more--it was bad enough in the 90's when I was a parts counterman,you always held your breath when you sold a customer a part from certain manufacturers that didn't have a real stellar reputation..counterfit parts were a big problem then,I remember some spark plugs we got in boxes that closely resembled AC plugs,but were some third world copy..
Buick is.
Well, I went and bought one of these.
https://www.innova.com/product/detail/5610/CarScan-Pro
Expensive little forker.
I just didn't like the phone app route. I do not like giving permissions to apps.
Hopefully this helps me out. And even if it doesn't on this truck, I'm sure it will down the road.
Little update.... My kid says that it'll start and run just fine. But if he hits any kind of bump it starts running like azz.
When he pulled it into the shop so we could check all the plugs and chase all the wiring I noticed a soft gravely rattle sound coming from the exhaust under his seat.
Then smelled real bad rotten eggs. I think his cat broke up inside and is causing plugage after a bump. If he shuts it off, waits a second and starts it back up it runs decent again. So next step after scanning it will probably be pull the Y pipe off and shake it out, see if any cat material falls out. If so the rest is getting beat out of both sides.
https://www.innova.com/product/detail/5610/CarScan-Pro
Expensive little forker.
I just didn't like the phone app route. I do not like giving permissions to apps.
Hopefully this helps me out. And even if it doesn't on this truck, I'm sure it will down the road.
Little update.... My kid says that it'll start and run just fine. But if he hits any kind of bump it starts running like azz.
When he pulled it into the shop so we could check all the plugs and chase all the wiring I noticed a soft gravely rattle sound coming from the exhaust under his seat.
Then smelled real bad rotten eggs. I think his cat broke up inside and is causing plugage after a bump. If he shuts it off, waits a second and starts it back up it runs decent again. So next step after scanning it will probably be pull the Y pipe off and shake it out, see if any cat material falls out. If so the rest is getting beat out of both sides.
yes that is possible, the cats in the y pipe. We have replaced move than a few in our fleet. thou a little newer than your son 05.
I've forgotten the numbers, but GM test for plugged exhaust (cat or further back) had been to check the exhaust pressure through the converter bung.
Pretty sure the limit was 3-4PSI. Anything above that there is a problem.
Pretty sure the limit was 3-4PSI. Anything above that there is a problem.
I draw the line 2.5 psi @2000 rpm
Thou that was for 90s vintage equip.
These days I smack'm with a dead blow any noise and it condemned.
Thou that was for 90s vintage equip.
These days I smack'm with a dead blow any noise and it condemned.
Pretty easy to take a temp gun and look at the temp at the front and rear of the cat. A plugged cat will have a much higher reading on the front side than the rear. A significant difference is not normal.
Rpm and vac look low to me. Is it running poor when this was scanned?
yes the bank 1 O2 sensors are reading the same voltage or close enough. mean cat is not changing the exhaust. Do the o2 sensor 1 voltage readings fluctuate ? Normal good reading should show voltage bounce above and below .5 volts.
It looks like that tool will let you graph the O2 signals, which will be much more meaningful. The S1 signals should be rapidly continually moving between 0 and 1V. The S2 signals should be slowly moving in that range. When a S1 and S2 look like they're in sync, the cat isn't working well. Have the cats been replaced? Because some "performance" cats don't affect the signal much, but work well enough the car doesn't stink.
