Do you bring your OBD toolkit when shopping for a used car?

[Mark R]

Is it considered appropriate etiquette to bring your lappy and techstream cable, and start hooking up when you go for a test drive?

I'm just thinking it might be a good idea to know if there is a history of trouble codes before you buy.

 

[Doppel]

By all means, though I doubt you'll get much of use from it really.

 

[satyajitmenon]

Don't see why not.

 

[HeXen]

if nothing else, the salesman will know your hardcore serious

 

[Raizinman]

Unless there is a CEL, check engine light, it will be pretty useless.

 

[halik]

I used vagcom on the last audi I bought.

 

[SparkyJJO]

Unless there is a CEL, check engine light, it will be pretty useless.

Not entirely true. There can be a code pending that hasn't triggered a light yet, or if you have the right OBD stuff you could see/chart realtime data streams that might hint towards something else that may not set a code right away but could indicate an issue.

 

[nismotigerwvu]

Not entirely true. There can be a code pending that hasn't triggered a light yet, or if you have the right OBD stuff you could see/chart realtime data streams that might hint towards something else that may not set a code right away but could indicate an issue.

This, especially if the seller keeps clearing the codes.

 

[razor2025]

I would bring it. I didn't have an OBD2 reader when I bought my WRX and low and behold, I had a CEL on the way home (drove 8 hours to FL, had mechanic inspect it before meeting). Would've caught that if I had checked for readiness when I was inspecting the car.

 

[cardiac]

I do it whenever shopping for a used vehicle. Caught a couple of bad 02 sensors when my niece was car shopping. Looked like they kept re-setting the CEL.... Had them knock off another $500 after we had talked them down pretty good...

 

[HybridSquirrel]

Unless there is a CEL, check engine light, it will be pretty useless.

you could check for stored fault codes. My brother bought his car at a shady dealership, and they removed the CEL bulb. Had 5 fault codes pop up on the obd scanner.

 

[SonicIce]

you could check for stored fault codes. My brother bought his car at a shady dealership, and they removed the CEL bulb. Had 5 fault codes pop up on the obd scanner.

lmao

 

[Doppel]

you could check for stored fault codes. My brother bought his car at a shady dealership, and they removed the CEL bulb. Had 5 fault codes pop up on the obd scanner.

Yeah but to be fair one of the faults was broken CEL bulb.

 

[T2urtle]

This, especially if the seller keeps clearing the codes.

I check for codes and then readiness. Of readiness is not set that means they just cleared something. So either drive til it sets or possibly pass on the car.

I've seen the missing bulb trick to cover up a p0420, catalyst fault

 

[sontakke]

Not only I take my OBD scanner with me on used car purchase, I even took it when I bought my new car with 11 miles on the clock! The EVAP monitor was incomplete at that time. I was wondering how the dealer was going to give me the sticker. It turns out that brand new cars do not go through emission in my state! So I never got to see the EVAP monitor incomplete on the inspection report :-(

 

[andylawcc]

you could check for stored fault codes. My brother bought his car at a shady dealership, and they removed the CEL bulb. Had 5 fault codes pop up on the obd scanner.

damn.

Yeah but to be fair one of the faults was broken CEL bulb.

hahaha

 

[ViviTheMage]

I've done it on the last Audi and the 135i I bought...F them, it's security!

 

[WhoBeDaPlaya]

Yeah but to be fair one of the faults was broken CEL bulb.

LMAO! Sig worthy 😀

 

[T2urtle]

Not only I take my OBD scanner with me on used car purchase, I even took it when I bought my new car with 11 miles on the clock! The EVAP monitor was incomplete at that time. I was wondering how the dealer was going to give me the sticker. It turns out that brand new cars do not go through emission in my state! So I never got to see the EVAP monitor incomplete on the inspection report :-(

a new car... eh. Bumper to bumper warranty. I'll still check but not with a fine tooth.

 

[CraigRT]

Honestly no.. I usually don't care when I am buying a car.. If it runs and drives fine I will usually buy it and just deal with any problems that come up.. It also helps that I enjoy working on cars, and that I do all the work myself.

So no, I would not bring my OBD2 shit with me. But that is just me.

 

[T2urtle]

^ its not that, its just extra cost on top of it. I mainly use it as leverage.

As long as its not a evap and cat issue.

 

[SparkyJJO]

Evap issue is usually not a big deal. Gas cap more often than anything. Except in my case it was a leaky fuel fill neck but I never have the easy fixes 😛

 

[T2urtle]

Evap issue is usually not a big deal. Gas cap more often than anything. Except in my case it was a leaky fuel fill neck but I never have the easy fixes 😛

I've almost never seen a gas cap as a fix. Most cases evap purge valve $50-250 and charcoal canister $250-350.

 

[sontakke]

I am battling P0446 on 99 Camry right now. The VSV on the canister was changed with no effect. Well, I bench tested the old VSV *afterwards* and it is good.

I did not want to get my hands dirty, so I let my mechanic talk me in to replacing the VSV as he assured me this would fix it. Now $100 is down the drain. I will have to take charge and figure it out myself.

So, do tell me more about your evap problems!

 

[T2urtle]

I am battling P0446 on 99 Camry right now. The VSV on the canister was changed with no effect. Well, I bench tested the old VSV *afterwards* and it is good.

I did not want to get my hands dirty, so I let my mechanic talk me in to replacing the VSV as he assured me this would fix it. Now $100 is down the drain. I will have to take charge and figure it out myself.

So, do tell me more about your evap problems!

If its a 4 cylinder, check the sensor on the block. Its mounted on the bottom of the engine. Between the back of the engine and firewall.