P0420 isuzu nqr. 2000 Isuzu Trooper with 170K miles. If you have IDSS just go into contr...

P0420 isuzu nqr. 2000 Isuzu Trooper with 170K miles. If you have IDSS just go into controller programming and you should be able to see if the software update is eligible. – Three way catalyst converter Bank 1 does not have enough oxygen storage capacity. They instruct to update the ECM software to fix the problem if no hard faults are present. P0420 indicates catalytic converter efficiency below threshold, often due to a failing converter or oxygen sensors. 2 model often faces repeated P0420 catalyst efficiency and P0240 turbo boost control issues causing power loss. 2018 Isuzu NQR Diesel Check Engine Light and Emissions Codes NQR diesel models often face DPF regeneration failures and catalytic converter efficiency issues. Fault codes P0420 and P2463 indicate SCR catalyst inefficiency and DEF system problems. Codes P31B1, P2463, and P0420 indicate diesel particulate filter (DPF) regeneration problems and catalytic converter inefficiency. Re: Isuzu NPR/NQR P0420 Posted to HD/Fleet Forum on 5/17/2018 Isuzu has a TSB for this P0420 code. zaq wil nnz fligki ulxmt bjql vocunif vhaha jaq evusc